Life In 19x19 :: The most difficult problem ever. Igo Hatsuyoron 120

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The most difficult problem ever. Igo Hatsuyoron 120 http://lifein19x19.com/viewtopic.php?f=17&t=4381	Page 3 of 4

Author:	Cassandra [ Mon Apr 15, 2024 2:55 am ]
Post subject:	Re: The most difficult problem ever. Igo Hatsuyoron 120
In January of this year, Ifuu Publishing transcribed and published a limited edition of "Igo Hatsuyôron, All / Reiwa transcription", based on what is considered THE ONLY SURVIVING COPY of Inoue Dôsetsu Inseki's "Igo Hatsuyôron" in Japan. Please find attached problem #120, including English translations of the original text in old Japanese. Please note that the "normal" text on the problems follows the pattern >>> "Black/White first, (ko,) result" but IH120 has >>> "Black first" only!!! And please don't overlook the further clue to the problem ) Attachment: IgoHatsuyôron120_EdoOriginal.jpg [ 81.77 KiB \| Viewed 26232 times ]

Author:	John Fairbairn [ Mon Apr 15, 2024 5:01 am ]
Post subject:	Re: The most difficult problem ever. Igo Hatsuyoron 120
For other readers, this new book is the result of research by 7-dan pro Kuwamoto Shinpei, who actually retired to become a local pro in Tottori. He found the original in a Buddhist library where it had been badly damaged by insects. The restoration is obviously a little tentative but there is interesting extra metadata on some other problems. I confess to finding the extra clue (which I assume to refer to the Kongming/Zhongda Three Kingdoms title) too obscure. But what I liked about Kuwamoto's work was that he found clues to how Dosetsu seems to have worked. Here is a lovely example. It is Problem 83 in the Fujisawa edition. It seems that Dosetsu got the idea for this problem from an actual game he played Honinbo Dochi. It was Game 6 of their 10-game match (game 1706-03-28a in the GoGoD database). Dosetsu played the triangled stone and Dochi had the good sense to answer it. He evidently saw a variation that merits a 5-star rating from Takagi Shoichi ("prefectural champion" standard, or about amateur 8-dan). Which tells us something about Dochi, too - he was just a young teenager (15 then but he had become 4-dan pro at age 11 or 12). The game adds a theme (seki) that doesn't come up in the lines normally shown for the solution.

Author:	Cassandra [ Mon Apr 15, 2024 6:33 am ]
Post subject:	Re: The most difficult problem ever. Igo Hatsuyoron 120
John Fairbairn wrote: I confess to finding the extra clue (which I assume to refer to the Kongming/Zhongda Three Kingdoms title) too obscure. Sorry, but I was referring to the explicit reference to the single Black stone that was captured earlier, which apparently did not survive further copying. + + + + + + + + + + Zhuge Liang == Black and Sima Yi == White ? Historically, the latter has triumphed over the former (says Wikipedia).

Author:	John Fairbairn [ Mon Apr 15, 2024 7:33 am ]
Post subject:	Re: The most difficult problem ever. Igo Hatsuyoron 120
Quote: Zhuge Liang == Black and Sima Yi == White ? Historically, the latter has triumphed over the former (says Wikipedia). I think we'd normally expect White to be given first, and Kongming's reputation was certainly greater than Zhongda's. But when Kongming died, Zhongda was besieging his army. As I recall, it seems that the likeliest story is that Kongming simply died of illness (a story overlaid by superstition because a meteorite was said to have fallen near the Shu army and would obviously have been taken as an omen). The leaderless Shu army then gave up. But the rival emperor wrote something about Kongming losing the battle and fatally vomiting blood. As always, history is written by the victors. Whether any of that provides a clue I know not. But normally problem titles do offer a clue or a description of the starting position. Other titles in the book relate to the same Three Kingdoms period, and it was around this time that yin-yang first became a "thing", so maybe it was just that Dosetsu had a fascination with that period (the Japanese yo element in the book name being Chinese yang, and his preface includes references to yin.

Author:	Cassandra [ Mon Apr 22, 2024 10:07 pm ]
Post subject:	Re: The most difficult problem ever. Igo Hatsuyoron 120
Updated the Igo Hatsuyôron 120 website with a new chapter about the new "Reiwa Complete Reprint Edition" and a new section "2024" on the "The Solution" page, showing several new sequences found by KataGo in games between Karl's 40b network from 2022 and my 60b network still in progress.

Author:	Cassandra [ Fri Jan 31, 2025 6:36 am ]
Post subject:	Re: The most difficult problem ever. Igo Hatsuyoron 120
In May 2024, I started training a 28b network using the training data previously generated by the 60b network. In July 2024, the 28b network had caught up (after a good 140 generations), so the self-play with the 60b network was terminated and continued with the 40b network. In October 2024, I then experienced massive hardware problems, which seriously slowed down further development. So I now concentrated the self-play training on the non-Main-Semeai variations, with a few more of these variations emerging from time to time in the games between Karl's 40b network and my 28b network. For some of these non-Main-Semeai variations, it seems to have been consolidated in the meantime that they represent valid solutions to the problem. I will publish details on this in subsequent posts.

Author: Cassandra [ Fri Jan 31, 2025 7:25 am ]

Post subject: Re: The most difficult problem ever. Igo Hatsuyoron 120

088094_F18A6

Click Here To Show Diagram Code: [go]$$Wm88 $$ +---------------------------------------+ $$ | . . . . 5 . . . . . . . X . . . O X . | $$ | . . . 6 2 1 . X O O . X O X O . . O . | $$ | . . . 4 3 X . O . . . X O . . O O . . | $$ | . X O , . . . . . O . X . O O X . . . | $$ | . . X X X X O O O . O X X . X X O O . | $$ | . X . O O O X X X O . . X . X O . a . | $$ | O O O O . X O O X X O O . O X . . Y . | $$ | O X . X . X . O O X O . . . X X X X X | $$ | O X . X . . . O X X O . X X X X O O O | $$ | X O O , . X . O X O O X X O O O O X . | $$ | X . . O X . . O X O . X O O O . X X X | $$ | X . . O X . . O X O . X O O X X X O O | $$ | X X O . X . . O X O . X O O O X X X O | $$ | 7 O O X O X . O X O . X X O O O X O O | $$ | . . X . . X . O X O X . O X X X O O O | $$ | O X X , X . . O X O O O O X O X O O X | $$ | . . . . O X . O X X X X X . O X X O X | $$ | O . X . . . X O O O O O O X O X . O X | $$ | . X . . . . . O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Black played the Gezumi :bt:

at the latest possible moment.
White did not follow the Main Semeai by answering locally at a, but immobilized Black's Nakade stones at the left edge by blocking with :w94:

, instead, usually inserting the sente sequence in the upper left corner after Yamada Shinji's Tsuke of :w88:

before.

The diagrams below show the most played lines in the games between the 28b and the 40b net.

Black = 28b / White = 40b Black = 40b / White = 28b

Click Here To Show Diagram Code: [go]$$Bm95 $$----------------------------------------–----------------------------------------- $$- . . . 5 O . . . . . . . X . . . O X . -- . . . 7 O . . . . . . . X . . . O X . - $$- . . . X X O 2 X O O . X O X O . . O . -- . . . X X O 4 X O O . X O X O . . O . - $$- . . . X O X . O . . . X O . . O O . . -- . . . X O X . O . . . X O . . O O . . - $$- . X O , . . . . . O . X . O O X . . . -- . X O , . . . . . O . X . O O X . . . - $$- . . X X X X O O O . O X X . X X O O . -- . . X X X X O O O . O X X . X X O O . - $$- . X . O O O X X X O . . X . X O 1 . . -- . X . O O O X X X O . . X . X O 1 2 . - $$- O O O O . X O O X X O O . O X . . X . -- O O O O . X O O X X O O . O X 3 . X . - $$- O X . X . X . O O X O . . . X X X X X -- O X . X . X . O O X O . . . X X X X X - $$- O X . X . . . O X X O . X X X X O O O -- O X . X . . . O X X O . X X X X O O O - $$- X O O , . X . O X O O X X O O O O X . -- X O O , . X . O X O O X X O O O O X . - $$- X . . O X . . O X O . X O O O . X X X -- X . . O X . . O X O . X O O O . X X X - $$- X 4 . O X . . O X O . X O O X X X O O -- X 6 . O X . . O X O . X O O X X X O O - $$- X X O 3 X . . O X O . X O O O X X X O -- X X O 5 X . . O X O . X O O O X X X O - $$- O O O X O X . O X O . X X O O O X O O -- O O O X O X . O X O . X X O O O X O O - $$- . . X . . X . O X O X . O X X X O O O -- . . X . . X . O X O X . O X X X O O O - $$- O X X , X . . O X O O O O X O X O O X -- O X X , X . . O X O O O O X O X O O X - $$- . . . . O X . O X X X X X . O X X O X -- . . . . O X . O X X X X X . O X X O X - $$- O . X . 7 6 X O O O O O O X O X . O X -- O . X . 9 8 X O O O O O O X O X . O X - $$- . X . . 9 8 0 O . . . . O X X X . O . -- . X . . . 0 . O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bm105 $$----------------------------------------–----------------------------------------- $$- . . . X O . . . . . . . X . . . O X . -- . . . X O . . . . . . . X 9 . . O X . - $$- . . . X X O O X O O . X O X O . . O . -- . . . X X O O X O O . X O X O . . O . - $$- . . . X O X . O . . . X O . . O O . . -- . . . X O X . O . . . X O 8 . O O . . - $$- . X O , 9 8 0 . . O . X . O O X . . . -- . X O , . . 3 . . O . X . O O X . . . - $$- 5 . X X X X O O O . O X X . X X O O . -- 7 . X X X X O O O . O X X . X X O O . - $$- 4 X . O O O X X X O . . X . X O X 1 2 -- 6 X . O O O X X X O . . X . X . X O . - $$- O O O O . X O O X X O O 3 O X . . X . -- O O O O . X O O X X O O 0 O X X . X . - $$- O X . X . X . O O X O . . . X X X X X -- O X . X . X . O O X O . . . X X X X X - $$- O X . X . . . O X X O . X X X X O O O -- O X . X . . . O X X O . X X X X O O O - $$- X O O , . X . O X O O X X O O O O X . -- X O O , . X . O X O O X X O O O O X . - $$- X . . O X . . O X O . X O O O . X X X -- X . . O X . . O X O . X O O O . X X X - $$- X O . O X . . O X O . X O O X X X O O -- X O . O X . . O X O . X O O X X X O O - $$- X X O X X . . O X O . X O O O X X X O -- X X O X X . . O X O . X O O O X X X O - $$- O O O X O X . O X O . X X O O O X O O -- O O O X O X . O X O . X X O O O X O O - $$- . . X . . X . O X O X . O X X X O O O -- . . X . . X . O X O X . O X X X O O O - $$- O X X , X 7 . O X O O O O X O X O O X -- O X X , X 5 . O X O O O O X O X O O X - $$- . . . . O X 6 O X X X X X . O X X O X -- . . . . O X 4 O X X X X X . O X X O X - $$- O . X . X O X O O O O O O X O X . O X -- O . X . X O X O O O O O O X O X . O X - $$- . X . . X O O O . . . . O X X X . O . -- . X . . 1 O 2 O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bm115 $$----------------------------------------–----------------------------------------- $$- . . . X O 7 . . . . . . X 9 . . O X . -- . . . X O 5 . . . . . 7 X X 6 . O X . - $$- . . . X X O O X O O . X O X O . . O . -- . . . X X O O X O O . X O X O . . O . - $$- . . . X . X . O . . . X O 8 . O O . . -- . . . X O X . O . . . X O O . O O . . - $$- . X O , X O O . . O . X . O O X 3 4 . -- . X O , . . X 3 4 O . X . O O X . . . - $$- X . X X X X O O O . O X X . X X O O . -- X . X X X X O O O . O X X . X X O O . - $$- O X . O O O X X X O 2 1 X . X O X X O -- O X . O O O X X X O . . X . X . X O . - $$- O O O O . X O O X X O O X O X . . X . -- O O O O . X O O X X O O O O X X . X . - $$- O X . X . X . O O X O . . . X X X X X -- O X . X . X . O O X O . . . X X X X X - $$- O X . X . . . O X X O . X X X X O O O -- O X . X . 9 . O X X O . X X X X O O O - $$- X O O , . X 0 O X O O X X O O O O X . -- X O O 0 . X 8 O X O O X X O O O O X . - $$- X . . O X . . O X O . X O O O . X X X -- X . . O X . . O X O . X O O O . X X X - $$- X O . O X . . O X O . X O O X X X O O -- X O . O X . . O X O . X O O X X X O O - $$- X X O X X . . O X O . X O O O X X X O -- X X O X X . . O X O . X O O O X X X O - $$- O O O X O X . O X O . X X O O O X O O -- O O O X O X . O X O . X X O O O X O O - $$- . . X . . X . O X O X . O X X X O O O -- . . X . . X . O X O X . O X X X O O O - $$- O X X , X X . O X O O O O X O X O O X -- O X X , X X . O X O O O O X O X O O X - $$- 6 5 . . O X O O X X X X X . O X X O X -- 2 1 . . O X O O X X X X X . O X X O X - $$- O . X . X O . O O O O O O X O X . O X -- O . X . X O . O O O O O O X O X . O X - $$- . X . . X O O O . . . . O X X X . O . -- . X . . X O O O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bm125 $$----------------------------------------–----------------------------------------- $$- . . . X . X . . . . . 3 X X 2 . O X . -- . . . X . X . . . . . X X X O . O X . - $$- . . . X X O O X O O . X O X O . . O . -- . . . X X O O X O O . X O X O . . O . - $$- . . . X . X . O . . . X O O . O O . . -- . . . X O X . O . . . X O O . O O . . - $$- . X O , X O O . . O . X . O O X X O . -- . X O , . . X X O O . X . O O X . . . - $$- X . X X X X O O O . O X X 4 X X O O . -- X . X X X X O O O . O X X . X X O O . - $$- O X . O O O X X X O O X X 5 X O X X O -- O X 5 O O O X X X O . . X . X . X O . - $$- O O O O . X O O X X O O X O X . . X . -- O O O O 4 X O O X X O O O O X X . X . - $$- O X . X . X . O O X O . . . X X X X X -- O X . X 2 X . O O X O . . . X X X X X - $$- O X . X . 1 . O X X O . X X X X O O O -- O X . X 3 X . O X X O . X X X X O O O - $$- X O O 6 . X O O X O O X X O O O O X . -- X O O O 1 X O O X O O X X O O O O X . - $$- X . . O X . . O X O . X O O O . X X X -- X 6 . O X . . O X O . X O O O . X X X - $$- X O . O X . . O X O . X O O X X X O O -- X O . O X . . O X O . X O O X X X O O - $$- X X O X X . . O X O . X O O O X X X O -- X X O X X . . O X O . X O O O X X X O - $$- O O O X O X . O X O . X X O O O X O O -- O O O X O X . O X O . X X O O O X O O - $$- . . X . . X . O X O X . O X X X O O O -- . . X . . X . O X O X . O X X X O O O - $$- O X X , X X . O X O O O O X O X O O X -- O X X , X X . O X O O O O X O X O O X - $$- O X . . O X O O X X X X X . O X X O X -- O X . . O X O O X X X X X . O X X O X - $$- O . X . X O . O O O O O O X O X . O X -- O . X . X O . O O O O O O X O X . O X - $$- . X . . X O O O . . . . O X X X . O . -- . X . . X O O O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bm131 $$----------------------------------------–----------------------------------------- $$- . . . X . X . . . . . X X X O . O X . -- . . . X . X . . . . . X X X O . O X . - $$- . . . X X O O X O O . X O X O . . O . -- . . . X X O O X O O 4 X O X O . . O . - $$- . . . X . X . O . . . X O O . O O . . -- . . . X O X 6 O . . 5 X O O . O O . . - $$- . X O , X O O . . O . X . O O X X O . -- . X O , . . X X O O 3 X . O O X 1 2 . - $$- X . X X X X O O O . O X X O X X O O . -- X . X X X X O O O . O X X . X X O O . - $$- O X . O O O X X X O O X X X X O X X O -- O X X O O O X X X O 8 7 X . X . X O . - $$- O O O O 6 X O O X X O O X O X . . X . -- O O O O O X O O X X O O O O X X . X . - $$- O X 7 X 2 X . O O X O . . . X X X X X -- O X . X O X . O O X O . . . X X X X X - $$- O X . X 3 X . O X X O . X X X X O O O -- O X . X X X . O X X O . X X X X O O O - $$- X O O O 1 X O O X O O X X O O O O X . -- . O O O X X O O X O O X X O O O O X . - $$- X 8 . O X . . O X O . X O O O . X X X -- . O . O X . . O X O . X O O O . X X X - $$- X O . O X . . O X O . X O O X X X O O -- . O . O X . . O X O . X O O X X X O O - $$- X X O X X . . O X O . X O O O X X X O -- . . O X X . . O X O . X O O O X X X O - $$- O O O X O X . O X O . X X O O O X O O -- O O O X O X . O X O . X X O O O X O O - $$- . . X . . X . O X O X . O X X X O O O -- . . X . . X . O X O X . O X X X O O O - $$- O X X , X X . O X O O O O X O X O O X -- O X X , X X . O X O O O O X O X O O X - $$- O X . 4 O X O O X X X X X . O X X O X -- O X . . O X O O X X X X X . O X X O X - $$- O . X . X O . O O O O O O X O X . O X -- O . X . X O . O O O O O O X O X . O X - $$- . X 5 . X O O O . . . . O X X X . O . -- . X . . X O O O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bm139 $$----------------------------------------–----------------------------------------- $$- . . . X . X 5 6 . . . X X X O . O X . -- . . . X . X 5 6 . . 2 X X X O . O X . - $$- . . . X X O O X O O . X O X O . . O . -- . . . X X O O X O O O X O X O . . O . - $$- . . . X . X . O . 4 3 X O O . O O . . -- . . . X O X O O 4 3 X X O O . O O . . - $$- . X O , X O O . . O . X . O O X X O . -- . X O , . 1 X X O O X X . O O X X O . - $$- X . X X X X O O O . O X X O X X O O . -- X . X X X X O O O . O X X . X X O O . - $$- O X 1 O O O X X X O O X X X X O X X O -- O X X O O O X X X O O X X . X . X O . - $$- O O O O O X O O X X O O X O X . . X . -- O O O O O X O O X X O O O O X X . X . - $$- O X X X O X . O O X O . . . X X X X X -- O X . X O X . O O X O . . . X X X X X - $$- O X . X X X . O X X O . X X X X O O O -- O X . X X X . O X X O . X X X X O O O - $$- 2 O O O X X O O X O O X X O O O O X . -- . O O O X X O O X O O X X O O O O X . - $$- . O . O X . . O X O . X O O O . X X X -- . O . O X . . O X O . X O O O . X X X - $$- . O . O X . . O X O . X O O X X X O O -- . O . O X . . O X O . X O O X X X O O - $$- . . O X X . . O X O . X O O O X X X O -- . . O X X . . O X O . X O O O X X X O - $$- O O O X O X . O X O . X X O O O X O O -- O O O X O X . O X O . X X O O O X O O - $$- . . X . . X . O X O X . O X X X O O O -- . . X . . X . O X O X . O X X X O O O - $$- O X X , X X . O X O O O O X O X O O X -- O X X , X X . O X O O O O X O X O O X - $$- O X . O O X O O X X X X X . O X X O X -- O X . . O X O O X X X X X . O X X O X - $$- O . X . X O . O O O O O O X O X . O X -- O . X . X O . O O O O O O X O X . O X - $$- . X X . X O O O . . . . O X X X . O . -- . X . . X O O O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bm145 $$----------------------------------------–----------------------------------------- $$- . . . X 1 X X O . 6 . X X X O . O X . -- . . . X 1 X X O . . O X X X O . O X . - $$- . . . X X O O . O O . X O X O . . O . -- . . . X X O O . O O O X O X O . . O . - $$- . . . X 3 X 2 O . O X X O O . O O . . -- . . . X O X O O O X X X O O . O O . . - $$- . X O , X O O . . O . X . O O X X O . -- . X O , . X X X O O X X . O O X X O . - $$- X . X X X X O O O . O X X O X X O O . -- X . X X X X O O O . O X X . X X O O . - $$- O X X O O O X X X O O X X X X O X X O -- O X X O O O X X X O O X X . X . X O 4 - $$- O O O O O X O O X X O O X O X . . X . -- O O O O O X O O X X O O O O X X . X . - $$- O X X X O X . O O X O 7 4 5 X X X X X -- O X . X O X . O O X O . . . X X X X X - $$- O X . X X X . O X X O . X X X X O O O -- O X . X X X . O X X O . X X X X O O O - $$- O O O O X X O O X O O X X O O O O X . -- . O O O X X O O X O O X X O O O O X . - $$- . O . O X . . O X O . X O O O . X X X -- . O . O X . . O X O . X O O O . X X X - $$- . O . O X . . O X O . X O O X X X O O -- . O . O X . . O X O . X O O X X X O O - $$- . . O X X . . O X O . X O O O X X X O -- . . O X X 3 2 O X O . X O O O X X X O - $$- O O O X O X . O X O . X X O O O X O O -- O O O X O X . O X O . X X O O O X O O - $$- . . X . . X . O X O X . O X X X O O O -- . . X . . X . O X O X . O X X X O O O - $$- O X X , X X . O X O O O O X O X O O X -- O X X , X X . O X O O O O X O X O O X - $$- O X . O O X O O X X X X X . O X X O X -- O X . . O X O O X X X X X . O X X O X - $$- O . X . X O . O O O O O O X O X . O X -- O 5 X . X O . O O O O O O X O X . O X - $$- . X X . X O O O . . . . O X X X . O . -- . X . . X O O O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Wm150 $$----------------------------------------–----------------------------------------- $$- . . . X X X X O . O . X X X O . O X . -- . . . X X X X O . . O X X X O . O X . - $$- . . . X X O O . O O . X O X O . . O . -- . . . X X O O . O O O X O X O . . O . - $$- . . . X X X O O . O X X O O . O O . . -- . . . X O X O O O X X X O O . O O . . - $$- . X O , X O O . . O 5 X . O O X X O . -- . X O , . X X X O O X X . O O X X O . - $$- X . X X X X O O O . O X X O X X O O 7 -- X . X X X X O O O . O X X 1 X X O O . - $$- O X X O O O X X X O O X X X X O X X O -- O X X O O O X X X O O X X 2 X . X O O - $$- O O O O O X O O X X O O X . X . . X . -- O O O O O X O O X X O O O O X X . X . - $$- O X X X O X . O O X O X 6 X X X X X X -- O X . X O X . O O X O . . . X X X X X - $$- O X . X X X . O X X O 3 X X X X O O O -- O X . X X X . O X X O . X X X X O O O - $$- O O O O X X O O X O O X X O O O O X . -- 3 O O O X X O O X O O X X O O O O X . - $$- . O . O X . . O X O . X O O O . X X X -- . O . O X . . O X O . X O O O . X X X - $$- . O . O X . . O X O . X O O X X X O O -- . O . O X . . O X O . X O O X X X O O - $$- . . O X X . . O X O . X O O O X X X O -- . . O X X X O O X O . X O O O X X X O - $$- O O O X O X . O X O . X X O O O X O O -- O O O X O X . O X O . X X O O O X O O - $$- . . X . . X . O X O X . O X X X O O O -- . . X . . X . O X O X . O X X X O O O - $$- O X X , X X . O X O O O O X O X O O X -- O X X , X X . O X O O O O X O X O O X - $$- O X . O O X O O X X X X X . O X X O X -- O X . . O X O O X X X X X . O X X O X - $$- O 4 X . X O . O O O O O O X O X . O X -- O X X . X O . O O O O O O X O X . O X - $$- . X X . X O O O . . . . O X X X . O . -- . X . . X O O O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Those who want to study this non-Main-Semeai variation any further on their own will find below compilations of all 28b/40b games ending in Jigo.

The comments indicate the number of games in which the respective variation was selected.
E.g. "A=19 // B=264" == Variation "A" was played in 19 games, variation "B" in 264 games.
(The labelling is designed for SGF-editors that label variations with capitals "A", "B", "C", ... Here, in the forum's SGF-browser's diagrams, you will have to take "1" as "A", "2" as "B, "3" as "C", ...)

Attachments:

IgoHatsuyoron120_088094_F18A6_28bWhite#199.sgf [120.97 KiB]
Downloaded 771 times

IgoHatsuyoron120_088094_F18A6_28bBlack#199.sgf [121.37 KiB]
Downloaded 756 times

Author: Cassandra [ Sat Feb 01, 2025 8:07 am ]

Post subject: Re: The most difficult problem ever. Igo Hatsuyoron 120

083095_A6N13

Click Here To Show Diagram Code: [go]$$Bm83 $$ +---------------------------------------+ $$ | . . . . . . . . . . . . e . . . O X . | $$ | . . . . . . . X O O . X O f W b . O . | $$ | . . . . . X . O . . . X c d . a O . . | $$ | . X O , . . . . . O . X . O O B . . . | $$ | . . X X X X O O O . O X X . X X O O . | $$ | . X . O O O X X X O . . X . X O . Q . | $$ | . O O O . X O O X X O O . O X . . Y . | $$ | O . . X . X . O O X O . . . X X X X X | $$ | . g . X . . . O X X O . X X X X O O O | $$ | X O O , . X . O X O O X X O O O O X . | $$ | X . . O X . . O X O . X O O O . X X X | $$ | X . . O X . . O X O . X O O X X X O O | $$ | X X O . X . . O X O . X O O O X X X O | $$ | 1 O O X O X . O X O . X X O O O X O O | $$ | 3 2 X . . X . O X O X . O X X X O O O | $$ | O X X , X . . O X O O O O X O X O O X | $$ | 4 . . . O X . O X X X X X . O X X O X | $$ | O . X . . . X O O O O O O X O X . O X | $$ | . X . . . . . O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

This is one of the "newer" non-Main-Semeai variations.
In the upper right, the Guzumi-Exchange :bt:

has already taken place, and Black also pushed into White's corner with :bc:

. White, however, fell back to :wc:

, instead of blocking at a. Black left the "usual" continuation for further reducing White's corner from Black a to White f for later.
At the left edge, Black started the Nakade Sequence with :b83:

at the bottom, instead of playing at g at the top.

Click Here To Show Diagram Code: [go]$$Bm87 $$ +---------------------------------------+ $$ | . . . . . . . . . . . . 9 . . . O X . | $$ | . . . . . . . X O O . X O 7 O 2 . O . | $$ | . . . . . X . O . . . X 3 8 . 1 O . . | $$ | . X O , . . . . . O . X . O O X . . . | $$ | . . X X X X O O O . O X X . X X O O . | $$ | . X . O O O X X X O . . X . X O . O . | $$ | . O O O . X O O X X O O . O X . . X . | $$ | O . . X . X . O O X O . . . X X X X X | $$ | . . . X . . . O X X O . X X X X O O O | $$ | X O O , . X . O X O O X X O O O O X . | $$ | X 4 . O X . . O X O . X O O O . X X X | $$ | X . 6 O X . . O X O . X O O X X X O O | $$ | X X O 5 X . . O X O . X O O O X X X O | $$ | X O O X O X . O X O . X X O O O X O O | $$ | X O X . . X . O X O X . O X X X O O O | $$ | O X X , X . . O X O O O O X O X O O X | $$ | O . . . O X . O X X X X X . O X X O X | $$ | O . X . . . X O O O O O O X O X . O X | $$ | . X . . . . . O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

leaves the Nakade-Sequence and starts the further reduction of White's upper right corner.
White, however, plays Tenuki with :w90:

, in order to immobilize Black's Nakade stones at the left edge.
Black is forced to secure one eye for his large group by capturing one White stone with :b95:

at the upper edge, ...

Click Here To Show Diagram Code: [go]$$Bm95 $$ +---------------------------------------+ $$ | . . . . . . . . . . . . X . . . O X . | $$ | . . . . . . . X O O . X . X O O . O . | $$ | . . . . . X . O . . . X X O 2 X O . . | $$ | . X O , . . . . . O . X . O O X . . . | $$ | . . X X X X O O O . O X X . X X O O . | $$ | . X . O O O X X X O . . X . X O . O . | $$ | . O O O . X O O X X O O 3 O X . . X . | $$ | O . . X . X . O O X O . . . X X X X X | $$ | . . . X . . . O X X O . X X X X O O O | $$ | X O O , . X . O X O O X X O O O O X . | $$ | X O . O X . . O X O . X O O O . X X X | $$ | X . O O X . . O X O . X O O X X X O O | $$ | X X O X X . . O X O . X O O O X X X O | $$ | X O O X O X . O X O . X X O O O X O O | $$ | X O X . . X . O X O X . O X X X O O O | $$ | O X X , X . . O X O O O O X O X O O X | $$ | O . . . O X . O X X X X X . O X X O X | $$ | O . X . . . X O O O O O O X O X . O X | $$ | . X . . . . . O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

... and the second one by arresting another White stone with :b97:

in the centre.

The diagrams below show the most played lines in the games between the 28b and the 40b net.

Black = 28b / White = 40b Black = 40b / White = 28b

Click Here To Show Diagram Code: [go]$$Wm96 $$---------------------------------------------------------------------------------- $$- . . . . . 4 . . . . . . X . . . O X . -- . . . . . 4 . 7 . . . . X . . . O X . - $$- . . . . 2 1 3 X O O . X . X O O . O . -- . . . . 2 1 3 X O O . X . X O O . O . - $$- . . . . . X 0 O . . . X X O O X O . . -- . . . 8 5 X 6 O . . . X X O O X O . . - $$- . X O , . . . . . O . X . O O X . . . -- . X O , . . . . . O . X . O O X . . . - $$- . . X X X X O O O . O X X . X X O O . -- . . X X X X O O O . O X X . X X O O . - $$- . X . O O O X X X O . . X . X O . O . -- . X . O O O X X X O . . X . X O . O . - $$- . O O O . X O O X X O O X O X . . X . -- . O O O . X O O X X O O X O X . . X . - $$- O . . X . X . O O X O . . . X X X X X -- O . . X . X . O O X O . . . X X X X X - $$- . . . X . . . O X X O . X X X X O O O -- . . . X . . . O X X O . X X X X O O O - $$- X O O , . X . O X O O X X O O O O X . -- X O O , . X . O X O O X X O O O O X . - $$- X O . O X . . O X O . X O O O . X X X -- X O . O X . . O X O . X O O O . X X X - $$- X . O O X . . O X O . X O O X X X O O -- X . O O X . . O X O . X O O X X X O O - $$- X X O X X . . O X O . X O O O X X X O -- X X O X X . . O X O . X O O O X X X O - $$- X O O X O X . O X O . X X O O O X O O -- X O O X O X . O X O . X X O O O X O O - $$- X O X . . X . O X O X . O X X X O O O -- X O X . . X . O X O X . O X X X O O O - $$- O X X , X . . O X O O O O X O X O O X -- O X X , X . . O X O O O O X O X O O X - $$- O . . . O X . O X X X X X . O X X O X -- O . . . O X . O X X X X X . O X X O X - $$- O . X . 6 5 X O O O O O O X O X . O X -- O . X . 0 9 X O O O O O O X O X . O X - $$- . X . . 8 7 9 O . . . . O X X X . O . -- . X . . . . . O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Wm106 $$---------------------------------------------------------------------------------- $$- . . . . . X . 1 . . . . X 6 5 . O X . -- . . . . . X . O . . . . X 4 3 . O X . - $$- . . . . X O O X O O 9 X . X O O . O . -- . . . . X O O . O O . X . X O O . O . - $$- . . . . . X X O . . . X X O O X O . . -- . . . X O X X O . . . X X O O X O . . - $$- . X O , . . 2 . . O . X . O O X . . . -- . X O , 0 . 6 9 . O . X . O O X . . . - $$- 8 . X X X X O O O . O X X . X X O O . -- . . X X X X O O O . O X X . X X O O . - $$- 7 X . O O O X X X O . . X . X O . O . -- . X . O O O X X X O . . X . X O . O . - $$- 0 O O O . X O O X X O O X O X . . X . -- . O O O . X O O X X O O X O X . . X . - $$- O . . X . X . O O X O . . . X X X X X -- O . . X . X . O O X O . . . X X X X X - $$- . . . X . . . O X X O . X X X X O O O -- . . . X . . . O X X O . X X X X O O O - $$- X O O , . X . O X O O X X O O O O X . -- X O O , . X . O X O O X X O O O O X . - $$- X O . O X . . O X O . X O O O . X X X -- X O . O X . . O X O . X O O O . X X X - $$- X . O O X . . O X O . X O O X X X O O -- X . O O X . . O X O . X O O X X X O O - $$- X X O X X . . O X O . X O O O X X X O -- X X O X X . . O X O . X O O O X X X O - $$- X O O X O X . O X O . X X O O O X O O -- X O O X O X . O X O . X X O O O X O O - $$- X O X . . X . O X O X . O X X X O O O -- X O X . . X . O X O X . O X X X O O O - $$- O X X , X 4 . O X O O O O X O X O O X -- O X X , X 8 . O X O O O O X O X O O X - $$- O . . . O X 3 O X X X X X . O X X O X -- O . . . O X 7 O X X X X X . O X X O X - $$- O . X . X O X O O O O O O X O X . O X -- O . X . X O X O O O O O O X O X . O X - $$- . X . . X O O O . . . . O X X X . O . -- . X . . 2 1 5 O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Wm116 $$---------------------------------------------------------------------------------- $$- . . . . . X . O . . . . X X O . O X . -- . . . . . X . O . . . . X X O . O X . - $$- . . . . X O O . O O O X . X O O . O . -- . . . . X O O . O O 3 X . X O O . O . - $$- . . . . 8 X X O . . . X X O O X O . . -- . . . X O X X O . . 0 X X O O X O . . - $$- . X O , . . X 6 7 O . X . O O X . . . -- . X O , X . X O . O . X . O O X 5 . . - $$- X . X X X X O O O . O X X . X X O O . -- . . X X X X O O O . O X X 1 X X O O . - $$- 2 X . O O O X X X O . . X . X O . O . -- 4 X . O O O X X X O . . X 2 X O . O . - $$- X O O O . X O O X X O O X O X . . X . -- 6 O O O . X O O X X O O X O X . . X . - $$- O . . X . X . O O X O . . . X X X X X -- O 7 . X . X . O O X O . . . X X X X X - $$- 3 5 4 X . . . O X X O . X X X X O O O -- 9 . . X . . . O X X O . X X X X O O O - $$- X O O , . X . O X O O X X O O O O X . -- X O O , . X . O X O O X X O O O O X . - $$- X O . O X . . O X O . X O O O . X X X -- X O . O X . . O X O . X O O O . X X X - $$- X 1 O O X . . O X O . X O O X X X O O -- X . O O X . . O X O . X O O X X X O O - $$- X X O X X . . O X O . X O O O X X X O -- X X O X X . . O X O . X O O O X X X O - $$- X O O X O X . O X O . X X O O O X O O -- X O O X O X . O X O . X X O O O X O O - $$- X O X . . X . O X O X . O X X X O O O -- X O X . . X . O X O X . O X X X O O O - $$- O X X , X X . O X O O O O X O X O O X -- O X X , X X . O X O O O O X O X O O X - $$- O 9 0 . O X O O X X X X X . O X X O X -- O . . . O X O O X X X X X . O X X O X - $$- O . X . X O . O O O O O O X O X . O X -- O 8 X . X O . O O O O O O X O X . O X - $$- . X . . X O O O . . . . O X X X . O . -- . X . . X O O O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Wm126 $$---------------------------------------------------------------------------------- $$- . . . . 8 X 7 O . . 9 . X X O . O X . -- . . . . . X . O . . 7 8 X X O . O X . - $$- . . . . X O O . O O O X . X O O . O . -- . . . . X O O . O O O X . X O O . O . - $$- . . . . X X X O . . . X X O O X O . . -- . . . X O X X O . 1 X X X O O X O . . - $$- . X O , . . X X O O . X . O O X 2 3 . -- . X O , X . X O . O . X . O O X O . . - $$- X . X X X X O O O . O X X 5 X X O O . -- . . X X X X O O O . O X X O X X O O . - $$- X X . O O O X X X O . 0 X 6 X O . O . -- X X . O O O X X X O . . X X X O . O 0 - $$- X O O O . X O O X X O O X O X . . X . -- X O O O 4 X O O X X O O X O X . . X . - $$- O . . X . X . O O X O . . . X X X X X -- O O . X . X . O O X O . . . X X X X X - $$- O O X X . 4 . O X X O . X X X X O O O -- O . 9 X . . . O X X O . X X X X O O O - $$- . O O , . X 1 O X O O X X O O O O X . -- X O O 5 6 X . O X O O X X O O O O X . - $$- . O . O X . . O X O . X O O O . X X X -- X O . O X . . O X O . X O O O . X X X - $$- . O O O X . . O X O . X O O X X X O O -- X 3 O O X . . O X O . X O O X X X O O - $$- . . O X X . . O X O . X O O O X X X O -- X X O X X . . O X O . X O O O X X X O - $$- . O O X O X . O X O . X X O O O X O O -- X O O X O X . O X O . X X O O O X O O - $$- . O X . . X . O X O X . O X X X O O O -- X O X . . X . O X O X . O X X X O O O - $$- O X X , X X . O X O O O O X O X O O X -- O X X , X X . O X O O O O X O X O O X - $$- O O X . O X O O X X X X X . O X X O X -- O 2 . . O X O O X X X X X . O X X O X - $$- O . X . X O . O O O O O O X O X . O X -- O X X . X O . O O O O O O X O X . O X - $$- . X . . X O O O . . . . O X X X . O . -- . X . . X O O O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Wm136 $$---------------------------------------------------------------------------------- $$- . . . . X X O O . . O 2 X X O . O X . -- . . . . . X . O . . O X X X O . O X . - $$- . . . . X O O . O O O X . X O O . O . -- . . . . X O O . O O O X . X O O . O . - $$- . . . . X X X O 9 8 6 X X O O X O . . -- . . . X O X X O . O X X X O O X O . . - $$- . X O , . . X X O O . X . O O X X O . -- . X O , X . X O . O 5 X . O O X O . . - $$- X . X X X X O O O . O X X O X X O O . -- . . X X X X O O O . O X X O X X O O 1 - $$- X X . O O O X X X O 1 X X X X O . O . -- X X . O O O X X X O . . X X X O . O X - $$- X O O O 5 X O O X X O O X O X . . X . -- X O O O X X O O X X O O X O X . . X 6 - $$- O . . X 7 X . O O X O . . . X X X X X -- O O . X . X 7 O O X O . 4 . X X X X X - $$- O O X X 0 X . O X X O . X X X X O O O -- O . O X . 8 2 O X X O . X X X X O O O - $$- . O O 3 4 X O O X O O X X O O O O X . -- . O O O X X 3 O X O O X X O O O O X . - $$- . O . O X . . O X O . X O O O . X X X -- . O . O X . . O X O . X O O O . X X X - $$- . O O O X . . O X O . X O O X X X O O -- . O O O X . . O X O . X O O X X X O O - $$- . . O X X . . O X O . X O O O X X X O -- . . O X X . . O X O . X O O O X X X O - $$- . O O X O X . O X O . X X O O O X O O -- . O O X O X . O X O . X X O O O X O O - $$- . O X . . X . O X O X . O X X X O O O -- . O X . . X . O X O X . O X X X O O O - $$- O X X , X X . O X O O O O X O X O O X -- O X X , X X . O X O O O O X O X O O X - $$- O O X . O X O O X X X X X . O X X O X -- O X . . O X O O X X X X X . O X X O X - $$- O . X . X O . O O O O O O X O X . O X -- O X X . X O . O O O O O O X O X . O X - $$- . X . . X O O O . . . . O X X X . O . -- . X . . X O O O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Wm146 $$----------------------------------------- $$- . . . . X X O O . . O X X X O . O X . - $$- . . . . X O O . O O O X . X O O . O . - $$- . . . . X X X O O X X X X O O X O . . - $$- . X O , . . X X O O . X . O O X X O . - $$- X . X X X X O O O . O X X O X X O O . - $$- X X 4 O O O X X X O O X X X X O . O 3 - $$- X O O O O X O O X X O O X O X . . X . - $$- O 5 . X O X . O O X O . 2 . X X X X X - $$- O O X X X X . O X X O . X X X X O O O - $$- . O O O X X O O X O O X X O O O O X . - $$- . O . O X . . O X O . X O O O . X X X - $$- . O O O X . . O X O . X O O X X X O O - $$- . . O X X . . O X O . X O O O X X X O - $$- . O O X O X . O X O . X X O O O X O O - $$- . O X . . X . O X O X . O X X X O O O - $$- O X X , X X . O X O O O O X O X O O X - $$- O O X . O X O O X X X X X . O X X O X - $$- O 1 X . X O . O O O O O O X O X . O X - $$- . X . . X O O O . . . . O X X X . O . - $$-----------------------------------------[/go]

Those who want to study this non-Main-Semeai variation any further on their own will find below compilations of all 28b/40b games ending in Jigo.

The comments indicate the number of games in which the respective variation was selected.
E.g. "A=138 // B=5" == Variation "A" was played in 138 games, variation "B" in 5 games.
(The labelling is designed for SGF-editors that label variations with capitals "A", "B", "C", ... Here, in the forum's SGF-browser's diagrams, you will have to take "1" as "A", "2" as "B, "3" as "C", ...)

Attachments:

IgoHatsuyoron120_083095_A6N13_28bWhite#199.sgf [58.09 KiB]
Downloaded 673 times

IgoHatsuyoron120_083095_A6N13_28bBlack#199.sgf [48.01 KiB]
Downloaded 663 times

Author:	RobertJasiek [ Sat Feb 01, 2025 10:59 am ]
Post subject:	Re: The most difficult problem ever. Igo Hatsuyoron 120
Do I understand it correctly that the problem is still far from being solved? What score does current research suggest and what was the originally believed score? What amount of total time have you spent on the problem thus far? How much all researchers together? What hardware, libraries and software have you been using for Katago? What is your current minimum number of visits per second? How much time have you let Katago search?

Author:	Cassandra [ Sat Feb 01, 2025 2:04 pm ]
Post subject:	Re: The most difficult problem ever. Igo Hatsuyoron 120
RobertJasiek wrote: Do I understand it correctly that the problem is still far from being solved? What do you understand by "solved"? Karl's training of his 40b network and my training of the (initially) 60b network (later 28b) followed completely different philosophies. Nevertheless, all came to an identical result: the Main Semeai is favoured, the best result for both sides is "White + 2" (with Komi = 1). In contrast to Karl, I was unable to find access to the “hintpos” support of the training, with which KataGo is able to detect its own incorrect evaluations. As a “substitute” I used the 60b/40b games (later 28b/40b), in which 40b could find the mistakes of 60b (28b). As an actually unintended side effect, non-Main-Semeai variations occasionally appeared in these games (usually initiated by 60b/28b), which (if played correctly) also end with "White + 2" (with Komi = 1). Are all basic non-Main-Semeai lines already known? No idea (probably not). In addition, many of the known ones (especially those that start early) have yet to undergo a (very lengthy) evaluation. RobertJasiek wrote: What score does current research suggest and what was the originally believed score? See above: "White + 2" (with Komi = 1). The "originally believed score" is hidden in the mists of history. Problem 120 is one of only two problems of Igo Hatsuyôron for which Inoue Dôsetsu Inseki did NOT give a result. It simply says “黒先” = “Black first”. We can only conclude from the (now known) title "孔明仲達勢" = "Zhuge Liang and Sima Yi" of the problem by consulting the history of ancient China that White is expected to maintain the upper hand.

Author:	RobertJasiek [ Sat Feb 01, 2025 2:50 pm ]
Post subject:	Re: The most difficult problem ever. Igo Hatsuyoron 120
A solution to a problem (and a presumed ruleset) is established by mathematical proof. Different degrees of solutions can be studied: weakest: proof of the correct score, without showing any complete sequence weak: proof for at least one stated sequence to construct the correct score strong: for all correct sequences to the correct score

Author:	Cassandra [ Mon Feb 03, 2025 2:45 pm ]
Post subject:	Re: The most difficult problem ever. Igo Hatsuyoron 120
RobertJasiek wrote: What hardware, libraries and software have you been using for Katago? What is your current minimum number of visits per second? How much time have you let Katago search? What task do you have in mind here?

Author:	RobertJasiek [ Mon Feb 03, 2025 2:52 pm ]
Post subject:	Re: The most difficult problem ever. Igo Hatsuyoron 120
Cassandra wrote: RobertJasiek wrote: What hardware, libraries and software have you been using for Katago? What is your current minimum number of visits per second? How much time have you let Katago search? What task do you have in mind here? Anything when you search for something larger than one local LD problem. E.g., when you do a whole board search. In particular then minimum number of visits per second. Libraries: versions of CUDA, CuDNN, TensorRT. Software: versions of KataGo and what model net, which Go GUI for calling KataGo. Hardware: uh, which GPU(s), to start with etc. Time: for all your H120 studies since you started many years ago.

Author:	Cassandra [ Tue Feb 04, 2025 7:46 am ]
Post subject:	Re: The most difficult problem ever. Igo Hatsuyoron 120
RobertJasiek wrote: Anything when you search for something larger than one local LD problem. E.g., when you do a whole board search. In particular then minimum number of visits per second. For the games between 60b/28b and 40b are combined: Colours: 40b = Black / 40b = White Thinking time: 60s/45s and 30s / 10s/7.5s and 5s / 2s/1.5s and 1s / 100/100 and 100 visits (seconds corresponding to the recpective net's size) "normal" PLAY / PLAY with additional parameters once recommemded by David for ANALYSIS, resulting in braoader, but less deaper search This results in 16 (complete) games per starting position (including continuations after corrected mistakes). "60s/45s and 30s" resulted in 10.000.000 down to x0.000 root visits per move. "Root visits per move" depends on the net, the position, and the familiarity of the net with the position, so "visits per second" does not really matter here (OK, a much stronger machine would be nice ...). RobertJasiek wrote: Libraries: versions of CUDA, CuDNN, TensorRT. Software: versions of KataGo and what model net, which Go GUI for calling KataGo. 60b-Selfplay used KataGo 13.x with suitable CUDA / CuDNN, 28b-Selfplay uses KataGo 14.1 with suitable TensorRT. The 60b/28b vs. 40b games are played with KataGo 14.1 with suitable CUDA / CuDNN via Sabaki. + + + + + + + + + + I think that Karl created a new 40b-version about every day. A new 60b-version was once created every two to three days. Now (after several hardware accidents) with a weaker machine than in the beginning a new 28b-version is created every week. Starting points were the strongest "normal" 60b / 28b nets available at that time in the KataGo repository.

Author:	Cassandra [ Wed Feb 05, 2025 11:45 am ]
Post subject:	Re: The most difficult problem ever. Igo Hatsuyoron 120
Attachment: 60b28bMistakes.jpg [ 60.46 KiB \| Viewed 7006 times ] This diagram shows the development of the number of mistakes when following the favoured moves in Sabaki's ANALYSIS mode (starting from the problem diagram) over the version / generation of KataGo's net. Blue is 60b, red is 28b. + + + + + + + + + + In the non-Main-Semeai variations posted above, a state has been reached in which there are only one or two lost games of 28b in the 16 28b/40b games per generation of the net (or none of course). Typical remaining mistakes of KataGo during PLAY with this problem are initiating a fake CHITOOM (not always playing the very same moves is not always the best policy here ) playing a PASS too early miscalculating the relationship of Main-Semeai-Liberties when on unfamiliar ground playing a fake forcing move

Author: Cassandra [ Fri Feb 07, 2025 10:26 pm ]

Post subject: Re: The most difficult problem ever. Igo Hatsuyoron 120

084_E15

Click Here To Show Diagram Code: [go]$$Bm77 $$ +---------------------------------------+ $$ | . . . . . . . . . . . . # . . . O X . | $$ | . . . . . . . X O O . X O @ W @ . O . | $$ | . . . . . X . O . . . X # @ . # O . . | $$ | . X O , . . . . . O . X . O O B . . . | $$ | . . X X Q X 2 O O . O X X . X X O O . | $$ | . X . O 4 O 1 X X O . . X . X O . . . | $$ | . O O O . 3 O O X X O O . O X . . Y . | $$ | O . . X . 5 . O O X O . . . X X X X X | $$ | . . . X . . . O X X O . X X X X X O O | $$ | X O O , . X . O X O O X X O O O O O . | $$ | X . . O X . . O X O . X O O O . X X X | $$ | X . . O X . . O X O . X O O X X X O O | $$ | X X . . X . . O X O . X O O O X X X O | $$ | . O O X O X . O X O . X X O O O X O O | $$ | . . X . . X . O X O X . O X X X O O O | $$ | O X X , X . . O X O O O O X O X O O X | $$ | . . . . O X . O X X X X X . O X X O X | $$ | O . X . . . X O O O O O O X O X . O X | $$ | . X . . . . . 6 . . . . O X X X . O . | $$ +---------------------------------------+[/go]

The Guzumi :bt:

has been played just before the termination of the Crosscut Sequence in the upper left centre.
Some time earlier, White answered Black's push :bc:

into her upper right corner with :wc:

. The rest of that reducition sequence :bs:

also took place here.
Finally, White pushed into Black's upper left corner from below with :wt:

.
Please note that the Guzumi could also be played one move earlier. In this case, the forcing exchange of / would be played immediately after / , not before.

The diagrams below show the most played lines in the games between the 28b and the 40b net.

Black = 28b / White = 40b Black = 40b / White = 28b

Click Here To Show Diagram Code: [go]$$Bm85 $$---------------------------------------------------------------------------------- $$- . . . . . . . . . . . . X . . . O X . -- . . . . . . . . . . . . X . . . O X . - $$- . . 9 8 . . . X O O . X O O O O . O . -- . . 9 8 . . . X O O . X O O O O . O . - $$- . 3 2 7 6 X . O . . . X X . . X O . . -- . 3 2 7 6 X . O . . . X X . . X O . . - $$- . X O 5 4 . . . . O . X . O O X . . . -- . X O 5 4 . . . . O . X . O O X . . . - $$- . . X X O X O O O . O X X . X X O O . -- . . X X O X O O O . O X X . X X O O . - $$- . X . O O O X X X O . . X . X O 1 . . -- . X . O O O X X X O . . X . X O 1 . . - $$- . O O O . X O O X X O O . O X . . X . -- . O O O . X O O X X O O . O X . . X . - $$- O . . X . X . O O X O . . . X X X X X -- O . . X . X . O O X O . . . X X X X X - $$- . . . X . . . O X X O . X X X X O O O -- . . . X . . . O X X O . X X X X O O O - $$- X O O , . X . O X O O X X O O O O X . -- X O O , . X . O X O O X X O O O O X . - $$- X . . O X . . O X O . X O O O . X X X -- X . . O X . . O X O . X O O O . X X X - $$- X . . O X . . O X O . X O O X X X O O -- X . . O X . . O X O . X O O X X X O O - $$- X X 0 . X . . O X O . X O O O X X X O -- X X 0 . X . . O X O . X O O O X X X O - $$- . O O X O X . O X O . X X O O O X O O -- . O O X O X . O X O . X X O O O X O O - $$- . . X . . X . O X O X . O X X X O O O -- . . X . . X . O X O X . O X X X O O O - $$- O X X , X . . O X O O O O X O X O O X -- O X X , X . . O X O O O O X O X O O X - $$- . . . . O X . O X X X X X . O X X O X -- . . . . O X . O X X X X X . O X X O X - $$- O . X . . . X O O O O O O X O X . O X -- O . X . . . X O O O O O O X O X . O X - $$- . X . . . . . O . . . . O X X X . O . -- . X . . . . . O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bm95 $$---------------------------------------------------------------------------------- $$- . . . . . . . . . . . . X . . . O X . -- . . . . . . . . . . . . X . . . O X . - $$- . . X O 0 . . X O O . X O O O . . O . -- . . X O 0 . . X O O . X O O O O . O . - $$- . X . X O X . O . . . X X . . X O . . -- . X . X O X . O . . . X X . . X O . . - $$- . X . X O . . . . O . X . O O X . . . -- . X . X O . . . . O . X . O O X . . . - $$- . . X X O X O O O . O X X . X X O O . -- . . X X O X O O O . O X X . X X O O . - $$- . X . O O O X X X O 2 1 X . X O X . . -- . X . O O O X X X O . . X . X O X 2 . - $$- . O O O . X O O X X O O . O X . . X . -- . O O O . X O O X X O O . O X 3 . X . - $$- O . . X . X . O O X O . . . X X X X X -- O . . X . X . O O X O . . . X X X X X - $$- . . . X . . . O X X O . X X X X O O O -- . . . X . . . O X X O . X X X X O O O - $$- X O O , . X . O X O O X X O O O O X . -- X O O , . X . O X O O X X O O O O X . - $$- X 8 . O X . . O X O . X O O O . X X X -- X 8 . O X . . O X O . X O O O . X X X - $$- X . . O X . . O X O . X O O X X X O O -- X . . O X . . O X O . X O O X X X O O - $$- X X O . X . . O X O . X O O O X X X O -- X X O . X . . O X O . X O O O X X X O - $$- 3 O O X O X . O X O . X X O O O X O O -- 1 O O X O X . O X O . X X O O O X O O - $$- 5 4 X . . X . O X O X . O X X X O O O -- 5 4 X . . X . O X O X . O X X X O O O - $$- O X X , X . . O X O O O O X O X O O X -- O X X , X . . O X O O O O X O X O O X - $$- 6 . . . O X . O X X X X X . O X X O X -- 6 9 . . O X . O X X X X X . O X X O X - $$- O 7 X . . . X O O O O O O X O X . O X -- O 7 X . . . X O O O O O O X O X . O X - $$- 9 X . . . . . O . . . . O X X X . O . -- . X . . . . . O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bm105 $$---------------------------------------------------------------------------------- $$- . . . . . . . . . . . . X . . . O X . -- . . . . . . . . . . . . X . . . O X . - $$- . . X O O . . X O O . X O O O O . O . -- . . X O O . . X O O . X O O O O . O . - $$- . X . X O X . O . . . X X . . X O . . -- . X . X O X . O . . . X X . . X O . . - $$- . X . X O . . . . O . X . O O X 0 . . -- . X . X O . . . . O . X . O O X . . . - $$- . . X X O X O O O . O X X . X X O O . -- 5 . X X O X O O O . O X X . X X O O . - $$- . X . O O O X X X O O X X . X O X 6 5 -- 4 X . O O O X X X O . . X . X . X O . - $$- . O O O . X O O X X O O 4 O X 7 . X . -- . O O O . X O O X X O O 7 O X X . X . - $$- O . . X . X . O O X O . . . X X X X X -- O . 6 X . X . O O X O . . . X X X X X - $$- . . . X . . . O X X O . X X X X O O O -- 8 . 0 X . . . O X X O . X X X X O O O - $$- X O O , . X . O X O O X X O O O O X . -- X O O , . X . O X O O X X O O O O X . - $$- X O . O X . . O X O . X O O O . X X X -- X O . O X . . O X O . X O O O . X X X - $$- X . 2 O X . . O X O . X O O X X X O O -- X . 2 O X . . O X O . X O O X X X O O - $$- X X O 1 X . . O X O . X O O O X X X O -- X X O 1 X . . O X O . X O O O X X X O - $$- X O O X O X . O X O . X X O O O X O O -- X O O X O X . O X O . X X O O O X O O - $$- X O X . . X . O X O X . O X X X O O O -- X O X . . X . O X O X . O X X X O O O - $$- O X X , X . . O X O O O O X O X O O X -- O X X , X . . O X O O O O X O X O O X - $$- O . . . O X 8 O X X X X X . O X X O X -- O X . . O X . O X X X X X . O X X O X - $$- O X X . . 9 X O O O O O O X O X . O X -- O X X . . . X O O O O O O X O X . O X - $$- X X . . . . 3 O . . . . O X X X . O . -- 9 X . . . . 3 O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bm115 $$---------------------------------------------------------------------------------- $$- . . 5 3 4 . . . . . . . X 0 . . O X . -- . . 3 1 2 . . . . . . . X . . . O X . - $$- . . X O O . . X O O . X O O O O . O . -- . . X O O . . X O O . X O O O O . O . - $$- . X . X O X . O . . . X X . . X O . . -- . X . X O X . O . . . X X . . X O . . - $$- . X . X O . . . . O . X . O O X O . . -- . X . X O . . . . O . X . O O X 4 . . - $$- . . X X O X O O O . O X X . X X O O . -- X 7 X X O X O O O . O X X 0 X X O O . - $$- 1 X . O O O X X X O O X X . X O X O X -- O X 6 O O O X X X O . . X . X . X O . - $$- . O O O . X O O X X O O O O X X . X . -- . O O O 5 X O O X X O O X O X X . X . - $$- O . 2 X . X . O O X O . . . X X X X X -- O . O X . X . O O X O . . . X X X X X - $$- . 8 7 X 9 . . O X X O . X X X X O O O -- O . O X . . . O X X O . X X X X O O O - $$- X O O , . X 6 O X O O X X O O O O X . -- X O O . . X . O X O O X X O O O O X . - $$- X O . O X . . O X O . X O O O . X X X -- X O . O X . . O X O . X O O O . X X X - $$- X . O O X . . O X O . X O O X X X O O -- X . O O X . . O X O . X O O X X X O O - $$- X X O X X . . O X O . X O O O X X X O -- X X O X X . . O X O . X O O O X X X O - $$- X O O X O X . O X O . X X O O O X O O -- X O O X O X . O X O . X X O O O X O O - $$- X O X . . X . O X O X . O X X X O O O -- X O X . . X . O X O X . O X X X O O O - $$- O X X , X . . O X O O O O X O X O O X -- O X X , X . . O X O O O O X O X O O X - $$- O . . . O X O O X X X X X . O X X O X -- O X . . O X 8 O X X X X X . O X X O X - $$- O X X . . X X O O O O O O X O X . O X -- O X X . . 9 X O O O O O O X O X . O X - $$- X X . . . . X O . . . . O X X X . O . -- X X . . . . X O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bm125 $$---------------------------------------------------------------------------------- $$- . . X X O . . . . . . 1 X O . . O X . -- . . X X O . . . 0 9 7 . X . . . O X . - $$- . . X O O . . X O O . X O O O O . O . -- . . X O O . . X O O 6 X O O O O . O . - $$- . X . X O X . O . 8 7 X X . . X O . . -- . X . X O X . O . . 8 X X . . X O . . - $$- . X . X O . . . . O . X . O O X O . 0 -- . X . X O . . . . O . X . O O X O . . - $$- . . X X O X O O O . O X X . X X O O 9 -- X X X X O X O O O . O X X O X X O O . - $$- X X . O O O X X X O O X X . X O X O X -- O X O O O O X X X O . . X 1 X . X O . - $$- . O O O 6 X O O X X O O O O X X . X . -- . O O O X X O O X X O O X O X X . X . - $$- O . O X . X 4 O O X O . . . X X X X X -- O . O X . X . O O X O . . . X X X X X - $$- 2 O X X X 5 . O X X O . X X X X O O O -- O . O X . 5 . O X X O . X X X X O O O - $$- X O O , . X O O X O O X X O O O O X . -- X O O 2 3 X 4 O X O O X X O O O O X . - $$- X O . O X . . O X O . X O O O . X X X -- X O . O X . . O X O . X O O O . X X X - $$- X . O O X . . O X O . X O O X X X O O -- X . O O X . . O X O . X O O X X X O O - $$- X X O X X . . O X O . X O O O X X X O -- X X O X X . . O X O . X O O O X X X O - $$- X O O X O X . O X O . X X O O O X O O -- X O O X O X . O X O . X X O O O X O O - $$- X O X . . X . O X O X . O X X X O O O -- X O X . . X . O X O X . O X X X O O O - $$- O X X , X . . O X O O O O X O X O O X -- O X X , X . . O X O O O O X O X O O X - $$- O 3 . . O X O O X X X X X . O X X O X -- O X . . O X O O X X X X X . O X X O X - $$- O X X . . X X O O O O O O X O X . O X -- O X X . . X X O O O O O O X O X . O X - $$- X X . . . . X O . . . . O X X X . O . -- X X . . . . X O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bm135 $$---------------------------------------------------------------------------------- $$- . . X X O . . . . 4 . X X O . . O X . -- . . X X O . . . O X X 1 X 2 . . O X . - $$- . . X O O . . X O O . X O O O O . O . -- . . X O O . . X O O O X O O O O . O . - $$- . X . X O X . O . O X X X . . X O . . -- . X . X O X . O . . O X X . . X O . . - $$- . X . X O . . . . O 3 X . O O X O . O -- . X . X O . . . . O 5 X . O O X O . . - $$- . . X X O X O O O . O X X . X X O O X -- X X X X O X O O O . O X X O X X O O 4 - $$- X X . O O O X X X O O X X . X O X O X -- O X O O O O X X X O . . X X X . X O 3 - $$- . O O O O X O O X X O O O O X X . X 1 -- 6 O O O X X O O X X O O X O X X . X 7 - $$- O . O X . X O O O X O . . . X X X X X -- O . O X . X . O O X O 0 8 9 X X X X X - $$- O O X X X X . O X X O . X X X X O O O -- O . O X . X . O X X O . X X X X O O O - $$- X O O 2 . X O O X O O X X O O O O X . -- X O O O X X O O X O O X X O O O O X . - $$- X O . O X . . O X O . X O O O . X X X -- X O . O X . . O X O . X O O O . X X X - $$- X . O O X . . O X O . X O O X X X O O -- X . O O X . . O X O . X O O X X X O O - $$- X X O X X 5 . O X O . X O O O X X X O -- X X O X X . . O X O . X O O O X X X O - $$- X O O X O X . O X O . X X O O O X O O -- X O O X O X . O X O . X X O O O X O O - $$- X O X . . X . O X O X . O X X X O O O -- X O X . . X . O X O X . O X X X O O O - $$- . X X , X . . O X O O O O X O X O O X -- O X X , X . . O X O O O O X O X O O X - $$- . X . . O X O O X X X X X . O X X O X -- O X . . O X O O X X X X X . O X X O X - $$- . X X . . X X O O O O O O X O X . O X -- O X X . . X X O O O O O O X O X . O X - $$- X X . . . . X O . . . . O X X X . O . -- X X . . . . X O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Those who want to study this non-Main-Semeai variation any further on their own will find below compilations of all 28b/40b games ending in Jigo.

The comments indicate the number of games in which the respective variation was selected.
E.g. "A=17 // B=23" == Variation "A" was played in 17 games, variation "B" in 23 games.
(The labelling is designed for SGF-editors that label variations with capitals "A", "B", "C", ... Here, in the forum's SGF-browser's diagrams, you will have to take "1" as "A", "2" as "B, "3" as "C", ...)

Attachments:

IgoHatsuyoron120_084_E15_28bWhite#199.sgf [17.36 KiB]
Downloaded 228 times

IgoHatsuyoron120_084_E15_28bBlack#199.sgf [17.76 KiB]
Downloaded 235 times

Author: Cassandra [ Sat Feb 08, 2025 2:16 am ]

Post subject: Re: The most difficult problem ever. Igo Hatsuyoron 120

082_E15

Click Here To Show Diagram Code: [go]$$Bm75 $$ +---------------------------------------+ $$ | . . . . . . . . . . . . # . . . O X . | $$ | . . . . . . . X O O . X O # @ . . O . | $$ | . . . . . X . O . . . X @ . . W O . . | $$ | . X O , . . . . . O . X . O O B . . . | $$ | . . X X Q X 2 O O . O X X . X X O O . | $$ | . X . O 4 O 1 X X O . . X . X O . . . | $$ | . O O O . 3 O O X X O O . O X . . Y . | $$ | O . . X . 5 . O O X O . . . X X X X X | $$ | . . . X . . . O X X O . X X X X O O O | $$ | X O O , . X . O X O O X X O O O O X . | $$ | X . . O X . . O X O . X O O O . X X X | $$ | X . . O X . . O X O . X O O X X X O O | $$ | X X . . X . . O X O . X O O O X X X O | $$ | . O O X O X . O X O . X X O O O X O O | $$ | . . X . . X . O X O X . O X X X O O O | $$ | O X X , X . . O X O O O O X O X O O X | $$ | . . . . O X . O X X X X X . O X X O X | $$ | O . X . . . X O O O O O O X O X . O X | $$ | . X . . . . . 6 . . . . O X X X . O . | $$ +---------------------------------------+[/go]

The Guzumi :bt:

has been played just before the termination of the Crosscut Sequence in the upper left centre.
Some time earlier, White answered Black's push :bc:

into her upper right corner with the "common" block :wc:

. The rest of that reducition sequence :bs:

also took place here.
Finally, White pushed into Black's upper left corner from below with :wt:

Click Here To Show Diagram Code: [go]$$Bm83 $$---------------------------------------------------------------------------------- $$- . . . . . . . . . . . . X . . . O X . -- . . . . . . . . . . . . X . . . O X . - $$- . . 9 8 . . . X O O . X O X O . . O . -- . . 9 8 . . . X O O . X O X O . . O . - $$- . 3 2 7 6 X . O . . . X O . . O O . . -- . 3 2 7 6 X . O . . . X O . . O O . . - $$- . X O 5 4 . . . . O . X . O O X . . . -- . X O 5 4 . . . . O . X . O O X . . . - $$- . . X X O X O O O . O X X . X X O O . -- . . X X O X O O O . O X X . X X O O . - $$- . X . O O O X X X O . . X . X O 1 . . -- . X . O O O X X X O . . X . X O 1 . . - $$- . O O O . X O O X X O O . O X . . X . -- . O O O . X O O X X O O . O X . . X . - $$- O . . X . X . O O X O . . . X X X X X -- O . . X . X . O O X O . . . X X X X X - $$- . . . X . . . O X X O . X X X X O O O -- . . . X . . . O X X O . X X X X O O O - $$- X O O , . X . O X O O X X O O O O X . -- X O O , . X . O X O O X X O O O O X . - $$- X . . O X . . O X O . X O O O . X X X -- X . . O X . . O X O . X O O O . X X X - $$- X . . O X . . O X O . X O O X X X O O -- X . . O X . . O X O . X O O X X X O O - $$- X X 0 . X . . O X O . X O O O X X X O -- X X 0 . X . . O X O . X O O O X X X O - $$- . O O X O X . O X O . X X O O O X O O -- . O O X O X . O X O . X X O O O X O O - $$- . . X . . X . O X O X . O X X X O O O -- . . X . . X . O X O X . O X X X O O O - $$- O X X , X . . O X O O O O X O X O O X -- O X X , X . . O X O O O O X O X O O X - $$- . . . . O X . O X X X X X . O X X O X -- . . . . O X . O X X X X X . O X X O X - $$- O . X . . . X O O O O O O X O X . O X -- O . X . . . X O O O O O O X O X . O X - $$- . X . . . . . O . . . . O X X X . O . -- . X . . . . . O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bm93 $$---------------------------------------------------------------------------------- $$- . . . . . . . . . . . . X . . . O X . -- . . . . . . . . . . . . X . . . O X . - $$- . . X O 0 . . X O O . X O X O . . O . -- . . X O 0 . . X O O . X O X O . . O . - $$- . X . X O X . O . . . X O . . O O . . -- . X . X O X . O . . . X O . . O O . . - $$- . X . X O . . . . O . X . O O X . . . -- . X . X O . . . . O . X . O O X . . . - $$- . . X X O X O O O . O X X . X X O O . -- . . X X O X O O O . O X X . X X O O . - $$- . X . O O O X X X O . . X . X O X . . -- . X . O O O X X X O . . X . X O X . . - $$- . O O O . X O O X X O O . O X . . X . -- . O O O . X O O X X O O . O X . . X . - $$- O . . X . X . O O X O . . . X X X X X -- O . . X . X . O O X O . . . X X X X X - $$- . . . X . . . O X X O . X X X X O O O -- . . . X . . . O X X O . X X X X O O O - $$- X O O , . X . O X O O X X O O O O X . -- X O O , . X . O X O O X X O O O O X . - $$- X 6 . O X . . O X O . X O O O . X X X -- X 6 . O X . . O X O . X O O O . X X X - $$- X . 8 O X . . O X O . X O O X X X O O -- X . 8 O X . . O X O . X O O X X X O O - $$- X X O 7 X . . O X O . X O O O X X X O -- X X O 7 X . . O X O . X O O O X X X O - $$- 1 O O X O X . O X O . X X O O O X O O -- 1 O O X O X . O X O . X X O O O X O O - $$- 3 2 X . . X . O X O X . O X X X O O O -- 3 2 X . . X . O X O X . O X X X O O O - $$- O X X , X . . O X O O O O X O X O O X -- O X X , X . . O X O O O O X O X O O X - $$- 4 . . . O X . O X X X X X . O X X O X -- 4 9 . . O X . O X X X X X . O X X O X - $$- O 5 X . . . X O O O O O O X O X . O X -- O 5 X . . . X O O O O O O X O X . O X - $$- 9 X . . . . . O . . . . O X X X . O . -- . X . . . . . O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bm103 $$---------------------------------------------------------------------------------- $$- . . . . . . . . . . . . X . . . O X . -- . . . . . . . . . . . . X 3 . . O X . - $$- . . X O O . . X O O . X O X O . . O . -- . . X O O . . X O O . X O X O . . O . - $$- . X . X O X . O . . . X O . . O O . . -- . X . X O X . O . . . X O 2 . O O . . - $$- 0 X . X O . . . . O . X . O O X 3 4 . -- . X . X O . . . . O . X . O O X 8 . . - $$- . . X X O X O O O . O X X . X X O O . -- . . X X O X O O O . O X X . X X O O . - $$- 6 X . O O O X X X O 8 7 X . X O X 2 . -- . X . O O O X X X O . . X . X O X 6 5 - $$- . O O O . X O O X X O O 9 O X 5 . X . -- . O O O . X O O X X O O 4 O X 7 . X . - $$- O . . X . X . O O X O . . . X X X X X -- O 0 9 X . X . O O X O . . . X X X X X - $$- . . . X . . . O X X O . X X X X O O O -- . . . X . . . O X X O . X X X X O O O - $$- X O O , . X . O X O O X X O O O O X . -- X O O , . X . O X O O X X O O O O X . - $$- X O . O X . . O X O . X O O O . X X X -- X O . O X . . O X O . X O O O . X X X - $$- X . O O X . . O X O . X O O X X X O O -- X . O O X . . O X O . X O O X X X O O - $$- X X O X X . . O X O . X O O O X X X O -- X X O X X . . O X O . X O O O X X X O - $$- X O O X O X . O X O . X X O O O X O O -- X O O X O X . O X O . X X O O O X O O - $$- X O X . . X . O X O X . O X X X O O O -- X O X . . X . O X O X . O X X X O O O - $$- O X X , X . . O X O O O O X O X O O X -- O X X , X . . O X O O O O X O X O O X - $$- O . . . O X . O X X X X X . O X X O X -- O X . . O X . O X X X X X . O X X O X - $$- O X X . . . X O O O O O O X O X . O X -- O X X . . . X O O O O O O X O X . O X - $$- X X . . . . 1 O . . . . O X X X . O . -- . X . . . . 1 O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bm113 $$---------------------------------------------------------------------------------- $$- . . . . . . . . . . . . X 5 3 6 O X . -- . 5 4 0 . . . . . . . . X X . . O X . - $$- . . X O O . . X O O . X O X O . . O . -- . . X O O . . X O O . X O X O . . O . - $$- 1 X . X O X . O . . . X O 4 . O O . . -- . X . X O X . O . . . X O O . O O . . - $$- O X . X O . . . . O . X . O O X X O . -- . X . X O . . . . O . X . O O X O . . - $$- 2 . X X O X O O O . O X X . X X O O . -- . . X X O X O O O . O X X . X X O O . - $$- O X . O O O X X X O O X X . X . X O . -- 3 X . O O O X X X O . . X . X . X O X - $$- . O O O . X O O X X O O X O X X . X . -- . O O O . X O O X X O O O O X X . X . - $$- O 8 7 X . X . O O X O . . . X X X X X -- O O X X . X . O O X O . . . X X X X X - $$- 0 . . X . . . O X X O . X X X X O O O -- . 2 1 X . . . O X X O . X X X X O O O - $$- X O O , . X . O X O O X X O O O O X . -- X O O 8 9 X . O X O O X X O O O O X . - $$- X O . O X . . O X O . X O O O . X X X -- X O . O X . . O X O . X O O O . X X X - $$- X . O O X . . O X O . X O O X X X O O -- X . O O X . . O X O . X O O X X X O O - $$- X X O X X . . O X O . X O O O X X X O -- X X O X X . . O X O . X O O O X X X O - $$- X O O X O X . O X O . X X O O O X O O -- X O O X O X . O X O . X X O O O X O O - $$- X O X . . X . O X O X . O X X X O O O -- X O X . . X . O X O X . O X X X O O O - $$- O X X , X . . O X O O O O X O X O O X -- O X X , X . . O X O O O O X O X O O X - $$- O 9 . . O X . O X X X X X . O X X O X -- O X . . O X 6 O X X X X X . O X X O X - $$- O X X . . . X O O O O O O X O X . O X -- O X X . . 7 X O O O O O O X O X . O X - $$- X X . . . . X O . . . . O X X X . O . -- . X . . . . X O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bm123 $$---------------------------------------------------------------------------------- $$- . . . 9 0 . . . . . . 1 X X X O O X . -- . X O 0 . . . . . . 9 3 X X 2 . O X . - $$- . . X O O . . X O O . X O X O . . O . -- . . X O O . . X O O 6 X O X O . . O . - $$- X X . X O X . O . . . X O O . O O . . -- . X . X O X . O . . 7 X O O . O O . . - $$- O X . X O . . . . O . X . O O X X O . -- . X . X O . . . . O 5 X . O O X O . . - $$- O . X X O X O O O . O X X . X X O O . -- . . X X O X O O O . O X X . X X O O 4 - $$- O X . O O O X X X O O X X . X . X O . -- X X . O O O X X X O . . X . X . X O X - $$- . O O O . X O O X X O O X O X X . X . -- . O O O 1 X O O X X O O O O X X . X . - $$- O O X X . X . O O X O . . . X X X X X -- O O X X . X . O O X O . . . X X X X X - $$- O 4 3 X . 7 . O X X O . X X X X O O O -- . O X X . 0 . O X X O . X X X X O O O - $$- X O O 8 . X 6 O X O O X X O O O O X . -- X O O O X X 8 O X O O X X O O O O X . - $$- X O . O X . . O X O . X O O O . X X X -- X O . O X . . O X O . X O O O . X X X - $$- X . O O X . . O X O . X O O X X X O O -- X . O O X . . O X O . X O O X X X O O - $$- X X O X X . . O X O . X O O O X X X O -- X X O X X . . O X O . X O O O X X X O - $$- X O O X O X . O X O . X X O O O X O O -- X O O X O X . O X O . X X O O O X O O - $$- X O X . . X . O X O X . O X X X O O O -- X O X . . X . O X O X . O X X X O O O - $$- . X X , X . . O X O O O O X O X O O X -- O X X , X . . O X O O O O X O X O O X - $$- . X . . O X 2 O X X X X X . O X X O X -- O X . . O X O O X X X X X . O X X O X - $$- . X X . . 5 X O O O O O O X O X . O X -- O X X . . X X O O O O O O X O X . O X - $$- X X . . . . X O . . . . O X X X . O . -- . X . . . . X O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bm133 $$---------------------------------------------------------------------------------- $$- . . 1 X O . . . 4 3 7 X X X X O O X . -- . X O O . . . . 6 5 X X X X O . O X . - $$- . . X O O . . X O O 6 X O X O . . O . -- . . X O O . . X O O O X O X O . . O . - $$- X X . X O X . O . . 8 X O O . O O . . -- . X . X O X . O 4 3 X X O O . O O . . - $$- O X . X O . . . . O 5 X . O O X X O . -- . X . X O . . . . O X X . O O X O . . - $$- O . X X O X O O O . O X X . X X O O . -- . . X X O X O O O . O X X . X X O O O - $$- O X . O O O X X X O O X X . X . X O 2 -- X X . O O O X X X O . . X . X . X O X - $$- . O O O . X O O X X O O X O X X . X . -- . O O O X X O O X X O O O O X X . X 7 - $$- O O X X 0 X . O O X O . . . X X X X X -- O O X X . X . O O X O . . . X X X X X - $$- O O X X . X . O X X O . X X X X O O O -- . O X X 1 O 2 O X X O . X X X X O O O - $$- X O O O 9 X O O X O O X X O O O O X . -- X O O O X X O O X O O X X O O O O X . - $$- X O . O X . . O X O . X O O O . X X X -- X O . O X . . O X O . X O O O . X X X - $$- X . O O X . . O X O . X O O X X X O O -- X . O O X . . O X O . X O O X X X O O - $$- X X O X X . . O X O . X O O O X X X O -- X X O X X . . O X O . X O O O X X X O - $$- X O O X O X . O X O . X X O O O X O O -- X O O X O X . O X O . X X O O O X O O - $$- X O X . . X . O X O X . O X X X O O O -- X O X . . X . O X O X . O X X X O O O - $$- . X X , X . . O X O O O O X O X O O X -- O X X , X . . O X O O O O X O X O O X - $$- . X . . O X O O X X X X X . O X X O X -- O X . . O X O O X X X X X . O X X O X - $$- . X X . . X X O O O O O O X O X . O X -- O X X . . X X O O O O O O X O X . O X - $$- X X . . . . X O . . . . O X X X . O . -- . X . . . . X O . . . . O X X X . O . - $$----------------------------------------------------------------------------------[/go]

Click Here To Show Diagram Code: [go]$$Bm143 $$ +---------------------------------------+ $$ | . . X X O . . . O X X X X X X O O X . | $$ | . . X O O . . X O O O X O X O . . O . | $$ | X X . X O X . O . . O X O O . O O . . | $$ | O X . X O . . . . O X X . O O X X O . | $$ | O X X X O X O O O . O X X O X X O O . | $$ | O X . O O O X X X O O X X X X . X O O | $$ | O O O O 2 X O O X X O O X O X X . X . | $$ | O O X X O X . O O X O . 3 . X X X X X | $$ | O O X X 1 X . O X X O . X X X X O O O | $$ | X O O O X X O O X O O X X O O O O X . | $$ | X O . O X . . O X O . X O O O . X X X | $$ | X . O O X . . O X O . X O O X X X O O | $$ | X X O X X . . O X O . X O O O X X X O | $$ | X O O X O X . O X O . X X O O O X O O | $$ | X O X . . X . O X O X . O X X X O O O | $$ | . X X , X . . O X O O O O X O X O O X | $$ | . X . . O X O O X X X X X . O X X O X | $$ | . X X . . X X O O O O O O X O X . O X | $$ | X X . . . . X O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Those who want to study this non-Main-Semeai variation any further on their own will find below compilations of all 28b/40b games ending in Jigo.

The comments indicate the number of games in which the respective variation was selected.
E.g. "A=13 // B=12 // C=279" == Variation "A" was played in 13 games, variation "B" in 12 games, and variation "C" in 279 games.
(The labelling is designed for SGF-editors that label variations with capitals "A", "B", "C", ... Here, in the forum's SGF-browser's diagrams, you will have to take "1" as "A", "2" as "B, "3" as "C", ...)

Attachments:

IgoHatsuyoron120_082_E15_28bWhite#203.sgf [111.28 KiB]
Downloaded 206 times

IgoHatsuyoron120_082_E15_28bBlack#203.sgf [128.02 KiB]
Downloaded 214 times

Author: Cassandra [ Sat Feb 08, 2025 2:29 am ]

Post subject: Re: The most difficult problem ever. Igo Hatsuyoron 120

082_E15
Both side's option for returning to the Main Semeai

In this non-Main-Semeai Variation, both sides may cooperate to return to the Main Semeai.

Click Here To Show Diagram Code: [go]$$Bm83 $$ +---------------------------------------+ $$ | . . . . . . . . . . . . X . . . O X . | $$ | . . 9 . . . . X O O . X O X O . . O . | $$ | . 3 2 8 7 X . O . . . X O . . O O . . | $$ | . X O 5 4 . . . . O . X . O O X . . . | $$ | . . X X O X O O O . O X X . X X O O . | $$ | . X . O O O X X X O . . X . X O 1 . a | $$ | . O O O . X O O X X O O 6 O X 0 . X . | $$ | O . . X . X . O O X O . . . X X X X X | $$ | . . . X . . . O X X O . X X X X O O O | $$ | X O O , . X . O X O O X X O O O O X . | $$ | X . . O X . . O X O . X O O O . X X X | $$ | X . . O X . . O X O . X O O X X X O O | $$ | X X . . X . . O X O . X O O O X X X O | $$ | . O O X O X . O X O . X X O O O X O O | $$ | . . X . . X . O X O X . O X X X O O O | $$ | O X X , X . . O X O O O O X O X O O X | $$ | . . . . O X . O X X X X X . O X X O X | $$ | O . X . . . X O O O O O O X O X . O X | $$ | . X . . . . . O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

White connects her single stone in the upper right centre with :w88:

, instead of following the non-Main-Semeai path with :w89:

.
Black blocks with :b89:

in the upper left corner, instead of following the non-Main-Semeai path by securing two eyes for his large group with a move at a at the right edge.

Click Here To Show Diagram Code: [go]$$Bm93 $$ +---------------------------------------+ $$ | . . . . . . . . . . . . X . . . O X . | $$ | . . X . . . . X O O . X O X O . . O . | $$ | . X O O X X . O . . . X O 2 . O O . . | $$ | . X O X O 3 . . . O . X . O O X . . . | $$ | . . X X O X O O O . O X X 1 X X O O . | $$ | . X . O O O X X X O . . X . X O X . . | $$ | 0 O O O . X O O X X O O O O X O . X . | $$ | O 9 . X . X . O O X O . . . X X X X X | $$ | 8 7 . X . . . O X X O . X X X X O O O | $$ | X O O , . X . O X O O X X O O O O X . | $$ | X . . O X . . O X O . X O O O . X X X | $$ | X . . O X . . O X O . X O O X X X O O | $$ | X X 4 . X . . O X O . X O O O X X X O | $$ | 5 O O X O X . O X O . X X O O O X O O | $$ | . 6 X . . X . O X O X . O X X X O O O | $$ | O X X , X . . O X O O O O X O X O O X | $$ | . . . . O X . O X X X X X . O X X O X | $$ | O . X . . . X O O O O O O X O X . O X | $$ | . X . . . . . O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Click Here To Show Diagram Code: [go]$$Bm103 $$ +---------------------------------------+ $$ | . . . . . . . . . . . . X . . . O X . | $$ | . . X . . . . X O O . X O X O . . O . | $$ | . X O O X X . O . . . X O O . O O . . | $$ | . X O X O X . . . O . X . O O X . . . | $$ | . . X X O X O O O . O X X X X X O O . | $$ | 0 X . O O O X X X O . . X . X O X . . | $$ | O O O O . X O O X X O O O O X O . X . | $$ | O X . X . X . O O X O . . . X X X X X | $$ | O X . X . . . O X X O . X X X X O O O | $$ | X O O 5 . X . O X O O X X O O O O X . | $$ | X 3 6 O X . . O X O . X O O O . X X X | $$ | X 7 . O X . . O X O . X O O X X X O O | $$ | X X O 4 X . . O X O . X O O O X X X O | $$ | X O O X O X . O X O . X X O O O X O O | $$ | 1 O X 8 . X . O X O X . O X X X O O O | $$ | O X X 9 X . . O X O O O O X O X O O X | $$ | 2 . . . O X . O X X X X X . O X X O X | $$ | O . X . . . X O O O O O O X O X . O X | $$ | . X . . . . . O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Click Here To Show Diagram Code: [go]$$Bm113 $$ +---------------------------------------+ $$ | . . . . 9 8 . . . . . 4 X 2 . . O X . | $$ | . . X . . 7 6 X O O . X O X O . . O . | $$ | . X O O X X . O . . . X O O . O O . . | $$ | . X O X O X . . . O . X . O O X . . . | $$ | 3 . X X O X O O O . O X X X X X O O . | $$ | O X . O O O X X X O . . X . X O X . . | $$ | O O O O 1 X O O X X O O O O X O . X . | $$ | O X . X . X . O O X O . . . X X X X X | $$ | O X . X . . . O X X O . X X X X O O O | $$ | X O O X . X . O X O O X X O O O O X . | $$ | X X O O X . . O X O . X O O O . X X X | $$ | X X . O X . . O X O . X O O X X X O O | $$ | X X O O X . . O X O . X O O O X X X O | $$ | X O O . O X . O X O . X X O O O X O O | $$ | X O X O 5 X . O X O X . O X X X O O O | $$ | O X X X X . . O X O O O O X O X O O X | $$ | O . . . O X . O X X X X X . O X X O X | $$ | O . X . . 0 X O O O O O O X O X . O X | $$ | . X . . . . . O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Click Here To Show Diagram Code: [go]$$Bm123 $$ +---------------------------------------+ $$ | . . . . X O 5 6 . . . O . O . . O X . | $$ | . . X . . X O X O O 0 X O . O . . O . | $$ | . X O O X X . O . . . X O O . O O . . | $$ | . X O X O X . . . O . X . O O X . . . | $$ | X . X X O X O O O . O X X X X X O O . | $$ | O X . O O O X X X O . . X . X O X . . | $$ | O O O O X X O O X X O O O O X O . X . | $$ | O X . X . X . O O X O . . . X X X X X | $$ | O X . X . . . O X X O . X X X X O O O | $$ | X O O X . X . O X O O X X O O O O X . | $$ | X X O O X . . O X O . X O O O . X X X | $$ | X X . O X . . O X O . X O O X X X O O | $$ | X X O O X . . O X O . X O O O X X X O | $$ | X O O 7 O X . O X O . X X O O O X O O | $$ | X O X O X X . O X O X . O X X X O O O | $$ | O X X X X 9 . O X O O O O X O X O O X | $$ | O . . . O X 8 O X X X X X . O X X O X | $$ | O . X . 1 O X O O O O O O X O X . O X | $$ | . X . . 3 2 4 O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Click Here To Show Diagram Code: [go]$$Bm133 $$ +---------------------------------------+ $$ | . . . . X . X O . . . O . O . . O X . | $$ | . . X . . X O . O O O X O . O . . O . | $$ | . X O O X X . O . . . X O O . O O . . | $$ | . X O X O X 1 . . O . X . O O X . . . | $$ | X . X X O X O O O . O X X X X X O O . | $$ | O X . O O O X X X O . . X . X O X . . | $$ | O O O O X X O O X X O O O O X O . X . | $$ | O X . X . X . O O X O . . . X X X X X | $$ | O X . X . . . O X X O . X X X X O O O | $$ | X O O X . X . O X O O X X O O O O X . | $$ | X X O O X . . O X O . X O O O . X X X | $$ | X X 2 O X . . O X O . X O O X X X O O | $$ | X X O O X . . O X O . X O O O X X X O | $$ | X O O X . X . O X O . X X O O O X O O | $$ | X O X . X X . O X O X . O X X X O O O | $$ | O X X X X X . O X O O O O X O X O O X | $$ | O . . . O X O O X X X X X . O X X O X | $$ | O . X . X O . O O O O O O X O X . O X | $$ | . X . . X O O O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Click Here To Show Diagram Code: [go]$$Bm135 $$ +---------------------------------------+ $$ | . . . . X . X O . . . O . O . . O X . | $$ | . . X 8 . X O . O O O X O . O . . O . | $$ | . X O O X X . O . . . X O O . O O . . | $$ | . X O X O X X 9 0 O . X . O O X . . . | $$ | X . X X O X O O O . O X X X X X O O . | $$ | O X . O O O X X X O . . X . X O X . . | $$ | O O O O X X O O X X O O O O X O . X . | $$ | O X . X . X . O O X O . . . X X X X X | $$ | O X . X . . . O X X O . X X X X O O O | $$ | 2 O O X . X . O X O O X X O O O O X . | $$ | 1 4 O O X . . O X O . X O O O . X X X | $$ | 5 3 O O X . . O X O . X O O X X X O O | $$ | 7 . O O X . . O X O . X O O O X X X O | $$ | . O O X . X . O X O . X X O O O X O O | $$ | 6 O X . X X . O X O X . O X X X O O O | $$ | O X X X X X . O X O O O O X O X O O X | $$ | O . . . O X O O X X X X X . O X X O X | $$ | O . X . X O . O O O O O O X O X . O X | $$ | . X . . X O O O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Click Here To Show Diagram Code: [go]$$Bm145 $$ +---------------------------------------+ $$ | . . . 3 X . X O . . . O . O . . O X . | $$ | . . X O 1 X O . O O O X O . O . . O . | $$ | . X O O X X . O . . . X O O . O O . . | $$ | . X O X O X X X O O 0 X . O O X 6 . . | $$ | X . X X O X O O O . O X X X X X O O . | $$ | O X 5 O O O X X X O . 2 X . X O X . . | $$ | O O O O X X O O X X O O O O X O . X . | $$ | O X . X . X . O O X O . 8 . X X X X X | $$ | O X . X . . . O X X O . X X X X O O O | $$ | O O O X . X . O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X . O O X . . O X O . X O O O X X X O | $$ | . O O X . X . O X O 4 X X O O O X O O | $$ | O O X . X X . O X O X . O X X X O O O | $$ | O X X X X X . O X O O O O X O X O O X | $$ | O 9 . . O X O O X X X X X . O X X O X | $$ | O 7 X . X O . O O O O O O X O X . O X | $$ | . X . . X O O O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Click Here To Show Diagram Code: [go]$$Bm155 $$ +---------------------------------------+ $$ | . . . X X . X O . . . O . O . . O X . | $$ | . . X . X X O . O O O X O . O . . O . | $$ | . X . . X X . O . . 8 X O O . O O . . | $$ | . X . X O X X X O O O X . O O X O . . | $$ | X . X X O X O O O . O X X X X X O O . | $$ | O X X O O O X X X O . O X . X O X 4 . | $$ | O O O O X X O O X X O O O O X O . X . | $$ | O X 7 X . X . O O X O . O . X X X X X | $$ | O X 5 X . 3 . O X X O 6 X X X X O O O | $$ | O O O X . X 2 O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X 1 O O X . . O X O . X O O O X X X O | $$ | 0 O O X . X . O X O O X X O O O X O O | $$ | O O X . X X . O X O X . O X X X O O O | $$ | O X X X X X . O X O O O O X O X O O X | $$ | O X . . O X O O X X X X X . O X X O X | $$ | O X X . X O . O O O O O O X O X . O X | $$ | 9 X . . X O O O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

...

Author: Cassandra [ Sat Feb 08, 2025 11:06 am ]

Post subject: Re: The most difficult problem ever. Igo Hatsuyoron 120

The other non-Main-Semeai variations

The other non-Main-Semeai variations still have a long way to go before consolidation, as the board is much emptier / more open and there are therefore many more variations to investigate.

046048_F2J3

Click Here To Show Diagram Code: [go]$$B $$ +---------------------------------------+ $$ | . . . . . . . . . . . . X . . . O X . | $$ | . . . . . . . X O O . X O X O . . O . | $$ | . . . . . X . O . . . X O . . O O . . | $$ | . X O , . . . . . O . X . O O X . . . | $$ | . . X X . X . . . . O X X . X X O O . | $$ | . X . O . O . . . . . . X . X O . . . | $$ | . O O O . . O O . . O O . O X . . Y . | $$ | O . . X . . . . . . . . . . X X X X X | $$ | . . . X . . . O . . O . X X X X O O O | $$ | X O O , . X . . . O . X X O O O O X . | $$ | X . . O X . . . . O . X O O O . X X X | $$ | X . . O X . . . X O . X O O X X X O O | $$ | X X . . X . . O . O . X O O O X X X O | $$ | . O O X O X . . . O . X X O O O X O O | $$ | . . X . . X . . . . X . O X X X O O O | $$ | O X X , X . . O . O O O O X O X O O X | $$ | . . . . O X B . W X X X X . O X X O X | $$ | O . X . . Q . . O O O O O X O X . O X | $$ | . X . . . . . . . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Really seems to come down to Jigo.
However, the question of whether :bc:

is actually the best answer to :wt:

still needs to be clarified.

046_J3

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . X . . . O X . | $$ | . . . . . . . X O O . X O X O . . O . | $$ | . . . . . X . O . . . X O . . O O . . | $$ | . X O , . . . . . O . X . O O X . . . | $$ | . . X X . X . . . . O X X . X X O O . | $$ | . X . O . O . . . . . . X . X O . . . | $$ | . O O O . . O O . . O O . O X . . Y . | $$ | O . . X . . . . . . . . . . X X X X X | $$ | . . . X . . . O . . O . X X X X O O O | $$ | X O O , . X . . . O . X X O O O O X . | $$ | X . . O X . . . . O . X O O O . X X X | $$ | X . . O X . . . X O . X O O X X X O O | $$ | X X . . X . . O . O . X O O O X X X O | $$ | . O O X O X . . . O . X X O O O X O O | $$ | . . X . . X . . . . X . O X X X O O O | $$ | O X X , X . . O . O O O O X O X O O X | $$ | . . . . O X . . Q X X X X . O X X O X | $$ | O . X . . . . . O O O O O X O X . O X | $$ | . X . . . . . . . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Seems to be a bit easier for Black than for White.

046_F2

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . X . . . O X . | $$ | . . . . . . . X O O . X O X O . . O . | $$ | . . . . . X . O . . . X O . . O O . . | $$ | . X O , . . . . . O . X . O O X . . . | $$ | . . X X . X . . . . O X X . X X O O . | $$ | . X . O . O . . . . . . X . X O . . . | $$ | . O O O . . O O . . O O . O X . . Y . | $$ | O . . X . . . . . . . . . . X X X X X | $$ | . . . X . . . O . . O . X X X X O O O | $$ | X O O , . X . . . O . X X O O O O X . | $$ | X . . O X . . . . O . X O O O . X X X | $$ | X . . O X . . . X O . X O O X X X O O | $$ | X X . . X . . O . O . X O O O X X X O | $$ | . O O X O X . . . O . X X O O O X O O | $$ | . . X . . X . . . a X . O X X X O O O | $$ | O X X , X . . O . O O O O X O X O O X | $$ | . . . . O X . . . X X X X . O X X O X | $$ | O . X . . Q . . O O O O O X O X . O X | $$ | . X . . . . . . . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Easier for Black than for White.
A move at a seems to be an interesting option for Black now.

044_K3

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . O X . | $$ | . . . . . . . X O O . X O . W W . O . | $$ | . . . . . X . O . . . X Y . . B O . . | $$ | . X O , . . . . . O . X . O O B . . . | $$ | . . X X . X . . . . O X X . X X O O . | $$ | . X . O . O . . . . . . X . X O . @ . | $$ | . O O O . . O O . . O O . O X . . # . | $$ | O . . X . . . . . . . . . . X X X X X | $$ | . . . X . . . O . . O . X X X X X O O | $$ | X O O , . X . . . O . X X O O O O O . | $$ | X . . O X . . . . O . X O O O . X X X | $$ | X . . O X . . . X O . X O O X X X O O | $$ | X X . . X . . O . O . X O O O X X X O | $$ | . O O X O X . . . O . X X O O O X O O | $$ | . . X . . X . . . . X . O X X X O O O | $$ | O X X , X . . O . O O O O X O X O O X | $$ | . . . . O X . . . Q X X X . O X X O X | $$ | O . X . . . . . O . O O O X O X . O X | $$ | . X . . . . . . . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Easier for Black than for White.

040_K3

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . O X . | $$ | . . . . . . . X O O . X O . . . . O . | $$ | . . . . . X . O . . . X . . . W O . . | $$ | . X O , . . . . . O . X . O O B . . . | $$ | . . X X . X . . . . O X X . X X O O . | $$ | . X . O . O . . . . . . X . X O . . . | $$ | . O O O . . O O . . O O . O X . . Y . | $$ | O . . X . . . . . . . . . . X X X X X | $$ | . . . X . . . O . . O . X X X X O O O | $$ | X O O , . X . . . O . X X O O O O X . | $$ | X . . O X . . . . O . X O O O . X X X | $$ | X . . O X . . . X O . X O O X X X O O | $$ | X X . . X . . O . O . X O O O X X X O | $$ | . O O X O X . . . O . X X O O O X O O | $$ | . . X . . X . . . . X . O X X X O O O | $$ | O X X , X . . O . O O O O X O X O O X | $$ | . . . . O X . . . Q X X X . O X X O X | $$ | O . X . . . . . O . O O O X O X . O X | $$ | . X . . . . . . . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Easier for White than for Black.

036_L3

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . O X . | $$ | . . . . . . . X O O . X O . . . . O . | $$ | . . . . . X . O . . . X . . . . O . . | $$ | . X O , . . . . . O . X . O O , . . . | $$ | . . X X . X . . . . O X X . X X O O . | $$ | . X . O . O . . . . . . X . X O . . . | $$ | . O O O . . O O . . O O . O X . . Y . | $$ | O . . X . . . . . . . . . . X X X X X | $$ | . . . X . . . O . . O . X X X X O O O | $$ | X O O , . X . . . O . X X O O O O X . | $$ | X . . O X . . . . O . X O O O . X X X | $$ | X . . O X . . . X O . X O O X X X O O | $$ | X X . . X . . O . O . X O O O X X X O | $$ | . O O X O X . . . O . X X O O O X O O | $$ | . . X . . X . . . . X . O X X X O O O | $$ | O X X , X . . O . , O O O X O X O O X | $$ | . . . . O X . . . . Q X X . O X X O X | $$ | O . X . . . . . O . O O O X O X . O X | $$ | . X . . . . . . . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Seems to come down to Jigo.

036_F2

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . O X . | $$ | . . . . . . . X O O . X O . . . . O . | $$ | . . . . . X . O . . . X . . . . O . . | $$ | . X O , . . . . . O . X . O O , . . . | $$ | . . X X . X . . . . O X X . X X O O . | $$ | . X . O . O . . . . . . X . X O . . . | $$ | . O O O . . O O . . O O . O X . . Y . | $$ | O . . X . . . . . . . . . . X X X X X | $$ | . . . X . . . O . . O . X X X X O O O | $$ | X O O , . X . . . O . X X O O O O X . | $$ | X . . O X . . . . O . X O O O . X X X | $$ | X . . O X . . . X O . X O O X X X O O | $$ | X X . . X . . O . O . X O O O X X X O | $$ | . O O X O X . . . O . X X O O O X O O | $$ | . . X . . X . . . . X . O X X X O O O | $$ | O X X , X . . O . , O O O X O X O O X | $$ | . . . . O X . . . . . X X . O X X O X | $$ | O . X . . Q . . O . O O O X O X . O X | $$ | . X . . . . . . . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Probably a "false positive".
BOTH nets win a lot of games with Black.

012_O5

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . O X . | $$ | . . . . . . . X O O . X O . . . . O . | $$ | . . . . . X . O . . . X . . . . O . . | $$ | . X O , . . . . . O . X . O O , . . . | $$ | . . X X . X . . . . O X X . X X O O . | $$ | . X . O . O . . . . . . X . X O . . . | $$ | . O O O . . O O . . O O . O X . . . . | $$ | O . . X . . . . . . . . . . X X X X X | $$ | . . . X . . . O . . O . X X X X . O O | $$ | X O O , . X . . . O . X . O O O O Y . | $$ | X . . O X . . . . O . X . . O . X X X | $$ | X . . O X . . . X O . X O O X X X O O | $$ | X X . . X . . O . O . X O . . . X X O | $$ | . O O X O X . . . O . . X O O . . O O | $$ | . . X . . X . . . . X . . Q X X O O O | $$ | O X X , X . . O . , O O O . O X O . X | $$ | . . . . O X . . . . . . . . . X X O X | $$ | O . X . . . . . O . . . O X O X . O . | $$ | . X . . . . . . . . . . O X X X . . . | $$ +---------------------------------------+[/go]

Easier for Black than for White.

011_O8

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . O X . | $$ | . . . . . . . X O O . X O . . . . O . | $$ | . . . . . X . O . . . X . . . . O . . | $$ | . X O , . . . . . O . X . O O , . . . | $$ | . . X X . X . . . . O X X . X X O O . | $$ | . X . O . O . . . . . . X . X O . . . | $$ | . O O O . . O O . . O O . O X . . . . | $$ | O . . X . . . . . . . . . . X X X X X | $$ | . . . X . . . O . . O . X X X X . O O | $$ | X O O , . X . . . O . X . O O O O . . | $$ | X . . O X . . . . O . X . . O . . X X | $$ | X . . O X . . . X O . X O Y . X X O O | $$ | X X . . X . . O . O . X O . . . X X O | $$ | . O O X O X . . . O . . X O O . X O O | $$ | . . X . . X . . . . X . . X X X O O O | $$ | O X X , X . . O . , O O O . O X O Q X | $$ | . . . . O X . . . . . . . . . X X O X | $$ | O . X . . . . . O . . . O X O X . O . | $$ | . X . . . . . . . . . . O X X X . . . | $$ +---------------------------------------+[/go]

Seems to be a bit easier for Black than for White.

010_O5

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . O X . | $$ | . . . . . . . X O O . X O . . . . O . | $$ | . . . . . X . O . . . X . . . . O . . | $$ | . X O , . . . . . O . X . O O , . . . | $$ | . . X X . X . . . . O X X . X X O O . | $$ | . X . O . O . . . . . . X . X O . . . | $$ | . O O O . . O O . . O O . O X . . . . | $$ | O . . X . . . . . . . . . . X X X X X | $$ | . . . X . . . O . . O . X X X X . O O | $$ | X O O , . X . . . O . X . O O O O Y . | $$ | X . . O X . . . . O . X . . O . X X X | $$ | X . . O X . . . X O . X O . . X X O O | $$ | X X . . X . . O . O . . . . . . X X O | $$ | . O O X O X . . . O . . X O O . X O O | $$ | . . X . . X . . . . X . . Q X X O O O | $$ | O X X , X . . O . , O O O . O X O O X | $$ | . . . . O X . . . . . . . . . X X O X | $$ | O . X . . . . . O . . . O X O X . O . | $$ | . X . . . . . . . . . . O X X X . . . | $$ +---------------------------------------+[/go]

Seems to be a bit easier for Black than for White.

009_N9

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . O X . | $$ | . . . . . . . X O O . X O . . . . O . | $$ | . . . . . X . O . . . X . . . . O . . | $$ | . X O , . . . . . O . X . O O , . . . | $$ | . . X X . X . . . . O X X . X X O O . | $$ | . X . O . O . . . . . . X . X O . . . | $$ | . O O O . . O O . . O O . O X . . . . | $$ | O . . X . . . . . . . . . . X X X X X | $$ | . . . X . . . O . . O . X X X X . O O | $$ | X O O , . X . . . O . X . O O O O . . | $$ | X . . O X . . . . O . X Y . O . . X X | $$ | X . . O X . . . X O . X O . X X X O O | $$ | X X . . X . . O . O . X O . . . X X O | $$ | . O O X O X . . . O . . X Q O . . O O | $$ | . . X . . X . . . . X . . . X X O O O | $$ | O X X , X . . O . , O O O . O X O . X | $$ | . . . . O X . . . . . . . . . X X O X | $$ | O . X . . . . . O . . . O X O X . O . | $$ | . X . . . . . . . . . . O X X X . . . | $$ +---------------------------------------+[/go]

Probably a "false positive".
BOTH nets win a lot of games with Black.

008_O5

Click Here To Show Diagram Code: [go]$$Bc $$ +---------------------------------------+ $$ | . . . . . . . . . . . . . . . . O X . | $$ | . . . . . . . X O O . X O . . . . O . | $$ | . . . . . X . O . . . X . . . . O . . | $$ | . X O , . . . . . O . X . O O , . . . | $$ | . . X X . X . . . . O X X . X X O O . | $$ | . X . O . O . . . . . . X . X O . . . | $$ | . O O O . . O O . . O O . O X . . . . | $$ | O . . X . . . . . . . . . . X X X X X | $$ | . . . X . . . O . . O . X X X X . O O | $$ | X O O , . X . . . O . X . O O O O Y . | $$ | X . . O X . . . . O . X . . O . X X X | $$ | X . . O X . . . X O . X O . . X X O O | $$ | X X . . X . . O . O . . . . . . X X O | $$ | . O O X O X . . . O . . X O O . . O O | $$ | . . X . . X . . . . X . . Q X X O O O | $$ | O X X , X . . O . , O O O . O X O . X | $$ | . . . . O X . . . . . . . . . X X O X | $$ | O . X . . . . . O . . . O X O X . O . | $$ | . X . . . . . . . . . . O X X X . . . | $$ +---------------------------------------+[/go]

Seems to be a bit easier for Black than for White.

Author: RobertJasiek [ Sat Feb 08, 2025 11:45 am ]

Post subject: Re: The most difficult problem ever. Igo Hatsuyoron 120

Sorry for playing the noob.

Click Here To Show Diagram Code: [go]$$Bm135 $$ +---------------------------------------+ $$ | . . . . X . X O . . . O . O . . O X . | $$ | . . X 8 . X O . O O O X O . O . . O . | $$ | . X O O X X . O . . . X O O . O O . . | $$ | . X O X O X X 9 0 O . X . O O X . . . | $$ | X . X X O X O O O . O X X X X X O O . | $$ | O X . O O O X X X O . . X . X O X . . | $$ | O O O O X X O O X X O O O O X O . X . | $$ | O X . X . X . O O X O . . . X X X X X | $$ | O X . X . . . O X X O . X X X X O O O | $$ | 2 O O X . X . O X O O X X O O O O X . | $$ | 1 4 O O X . . O X O . X O O O . X X X | $$ | 5 3 O O X . . O X O . X O O X X X O O | $$ | 7 . O O X . . O X O . X O O O X X X O | $$ | . O O X . X . O X O . X X O O O X O O | $$ | 6 O X . X X . O X O X . O X X X O O O | $$ | O X X X X X . O X O O O O X O X O O X | $$ | O . . . O X O O X X X X X . O X X O X | $$ | O . X . X O . O O O O O O X O X . O X | $$ | . X . . X O O O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Why would 36 at 41 fail?

Click Here To Show Diagram Code: [go]$$Bm155 $$ +---------------------------------------+ $$ | . . . X X . X O . . . O . O . . O X . | $$ | . . X . X X O . O O O X O . O . . O . | $$ | . X . . X X . O . . 8 X O O . O O . . | $$ | . X . X O X X X O O O X . O O X O . . | $$ | X . X X O X O O O . O X X X X X O O . | $$ | O X X O O O X X X O . O X . X O X 4 . | $$ | O O O O X X O O X X O O O O X O . X . | $$ | O X 7 X . X . O O X O . O . X X X X X | $$ | O X 5 X . 3 . O X X O 6 X X X X O O O | $$ | O O O X . X 2 O X O O X X O O O O X . | $$ | X O O O X . . O X O . X O O O . X X X | $$ | X X O O X . . O X O . X O O X X X O O | $$ | X 1 O O X . . O X O . X O O O X X X O | $$ | 0 O O X . X . O X O O X X O O O X O O | $$ | O O X . X X . O X O X . O X X X O O O | $$ | O X X X X X . O X O O O O X O X O O X | $$ | O X . . O X O O X X X X X . O X X O X | $$ | O X X . X O . O O O O O O X O X . O X | $$ | 9 X . . X O O O . . . . O X X X . O . | $$ +---------------------------------------+[/go]

Why does White postpone dissolution of the hane-seki as long as possible?

If White will dissolve the hane-seki, why does he play all the approach moves in the upper right?

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