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 Post subject: Re: This 'n' that
Post #521 Posted: Sun Nov 25, 2018 11:47 am 
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Winona Adkins and kitty


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This post by Bill Spight was liked by 7 people: BlindGroup, daal, dfan, EdLee, Elom, jeromie, Kirby
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Post #522 Posted: Mon Nov 26, 2018 10:55 pm 
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Thank you, Bill, for the pictures. It's nice to put some names to faces.

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Post #523 Posted: Thu Feb 14, 2019 10:40 am 
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Dear Friends and Gentle Hearts,

A little Valentine's present. :)

https://www.youtube.com/watch?v=WWLPwEF ... gs=pl%2Cwn

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I think it's a great idea to talk during sex, as long as it's about snooker.

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 Post subject: Re: This 'n' that
Post #524 Posted: Sun Mar 31, 2019 2:56 pm 
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Many thanks to Daniel Hu for his thoughts about AlphaGo and strategy. :) viewtopic.php?f=10&t=16527

I think that we humans will come up new and useful ideas and concepts about go, based upon the play and opinions of bots, even if they cannot explain their plays and preferences. Hats off to Daniel for making steps in that direction.

I doubt if Elf (version 1, anyway) is as strong as AlphaGo, but the Elf team has given us a lot of material to study with its commentary on most of the GoGoD games. The commentary does not include handicap games, and its view of even games without komi is, perforce, flawed, as it was trained on 7.5 komi. I have also found a ladder mistake, BTW. ;)

One remark in the paper by the Elf team has made a slight difference in my view of the frequent tenukis of Zero bots. It was that Elf learned go backwards, in a sense, because it learned to predict the winner of the game, and early in its training it was, OC, better at that near the end of the game than early in the game. (This does not prevent it from making wacko endgame plays, OC. ;)) I filled in the blanks a little bit in that explanation, BTW.

The endgame, as we humans know, is the phase of the game in which, except for ko positions, the board is divided into independent or nearly independent regions. In each of these regions one play, or maybe a few plays are made, and then a player tenukis, because plays in that region have become worth less, or, as we say, the local temperature has dropped.

It is quite possible, then, that zero bots, who have not been trained on human games, view the go board is a number of quasi-independent regions, even in the opening. (I do so, myself, BTW. :)) Perhaps they do so even more than humans. Quien sabe? If so, that would explain their greater propensity to play tenuki than humans have.

Are humans wrong not to tenuki so much? Maybe, maybe not. To understand one reason why not we need to address the question of the margin of error of the bots' evaluations. (Nobody knows what the margin of error is, OC, because it has not been studied directly. IMHO, the margin of error of the winrate estimates of the AlphaGo teaching tool is at least 2%, and that of the winrate estimates of the Elf commentary is around 3%.) That is, if you are a human and Elf or Leela Zero says that you have made a 2% mistake, you may well have made the right play, and even if your move was an "inaccuracy", it may not cost any points with perfect play afterwards, and even if it does cost a point or two, it may not cost the game. That is especially so in the opening. OC, the bot as a player has to trust its evaluations, in accordance with its algorithms. So the bot may well tenuki (correctly) even when it does not actually need to do so, and a human in the same position would not be inclined to tenuki.

----

Here is a position when Takagawa, a player who understood the opening about as well as any human in the 20th century did, failed to tenuki, and Elf thinks that it was a 9% error. I'll go with Elf on this one. 9% is surely outside of its margin of error.

Click Here To Show Diagram Code
[go]$$Bc Maeda (W) vs. Takagawa, 1951/07/01
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 2 . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . 1 . . . |
$$ | . . . 0 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 9 . . . . . . . . . . . . . . . |
$$ | . . . . 7 . . . . . . . . . . . . . . |
$$ | . . . 5 6 . . . . . . . . . . . . . . |
$$ | . . . , 8 . . . . , . . . . . 3 . . . |
$$ | . . . 4 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


You can probably guess Takagawa's error, since he did not have many opportunities to make one. ;) (It was :b9:.) But where should he have played :b9:, and why, according to Elf?

Click Here To Show Diagram Code
[go]$$Bcm9 Tenuki, Zwischenzug
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . 6 . . . . . . . . . . . . . |
$$ | . . 4 , . . . . . , . . . . . X . . . |
$$ | . . 2 1 . . . . . . . . . . . . . . . |
$$ | . . 3 5 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 7 . . . . . . . . . . . . . . . . |
$$ | . . . . X a . . . . . . . . . . . . . |
$$ | . . b X O . . . . . . . . . . . . . . |
$$ | . . . , O . . . . , . . . . . X . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


According to Elf, Takagawa should have played the high approach to the top left corner with :b9:, anticipating the following joseki, and then come back to play the third line keima with :b15:. Later Elf anticipates the exchange, Black "a" - White "b". OC, Elf appreciates the relationship between the Black thickness in the top left and the Black thickness in the bottom left, but so do humans. But Takagawa did not realize the fact that the Black stones in the top left corner do not need an extension. (He even wrote about when stones need an extension, so I am pretty sure of what he thought. :)) That shape had been played without an extension a few times in go history, but it was AlphaGo who taught us that it does not need one, and an extension should frequently be omitted.


This was also the game where Elf missed the ladder.

Click Here To Show Diagram Code
[go]$$Bcm21 Ladder Breaker
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . 5 8 . |
$$ | . . . , . . . . . , . . . . 3 X 4 . . |
$$ | . . . O . . . . . . . . . . 7 2 6 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . X X . . . . . . . . . . . . . . |
$$ | . . O X O . . . . . . . . . . . . . . |
$$ | . . O X O 1 . . . , . . . . . X . . . |
$$ | . O O O X . . . . . . . . . . . . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Maeda played :w22: as a ladder breaker. :b23:, OC, restored the ladder. Elf wants to play :b27: at 28. :shock:

Edit: Let me add this.

Click Here To Show Diagram Code
[go]$$Bcm27 Ladder Broken variation
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . 3 . . . . . . X 1 . |
$$ | . . . , . . . . . , . . . . X X O . . |
$$ | . . . O . . . . . . . . . . 4 O O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 2 . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . X X . . . . . . . . . . . . . . |
$$ | . . O X O . . . . . . . . . . . . . . |
$$ | . . O X O X . . . , . . . . . X . . . |
$$ | . O O O X . . . . . . . . . . . . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


One Elf variation has :b29: at 30, restoring the ladder, but this one has White play :w30: instead of running out in the broken ladder. (This variations has only a small change in winrate.)

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 Post subject: Re: This 'n' that
Post #525 Posted: Mon Apr 01, 2019 2:37 am 
Oza

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Hi, Bill

I have printed out Daniel's paper to read on my next train journey, but as you have endorsed it I shall try to get to it sooner! I have a few remarks below on what you said, which obviously are made in ignorance of what Daniel may have said.

First, the trivial points. The move order shown for the Takagawa game (vs Maeda) is wrong, but of more substance is the fact that komi was only 4.5. Given that, which you correctly (as confirmed by the Elf programmer) see as a flaw, plus an apparent ladder error by Elf, I'm wondering how much we can rely on Elf being right here and Takagawa wrong.

Now the meatier points. You use the word thickness about Takagawa's play. It has been my impression that he himself tended to use that term far less than other players (and conversely used terms such a balance much more than other players). I put it to you that it's not real thickness (it's gaisei) and so the "rules" about local plays around thickness (such as extensions) actually tended to be either ignored by Takagawa or were subsumed in his views about balance. I think that has obvious implications for how we view AI moves in the whole nexus spanning thickness, influence, walls, thinness, etc. Even in the traditional human thinking on the topic, there is room for deeper consideration (e.g. the fact that thinness is not actually the antonym of thickness), but in any case the heuristics for playing around influence differ from playing around true thickness. I suggest bots may be doing that more reliably than humans.

Further (to take up your point about regions), one of the main tenets of New Fuseki theory was equilibrium and averaging based on symmetries (which, too, has a bearing on balance). Theorists then therefore made much of dividing the board diagonally rather than orthogonally, yet that idea seems to have been largely forgotten. Players today (even pros) seem focused still on viewing the board as four square quadrants, which I think is partly to do with obsession about josekis. But if you view the board as four equilateral triangles you get a very different view - perhaps one more like the one the bots are "seeing" but which may still be within the purview of humans?

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 Post subject: Re: This 'n' that
Post #526 Posted: Mon Apr 01, 2019 6:15 am 
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Hi, John

Would you care to expound a bit on how viewing the board split diagonally might lead to some different assessments? Perhaps you could point to some theoretical works translated into English?

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Post #527 Posted: Mon Apr 01, 2019 6:35 am 
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John Fairbairn wrote:
But if you view the board as four equilateral triangles


I usually don't view the board this way.

Attachment:
equilateral.JPG
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Post #528 Posted: Mon Apr 01, 2019 10:03 am 
Oza

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Sorry, I was slipshod and used equilateral for isosceles. Like numbers, geometry falls into the class of things I have to stop and think about. The advantage is that I can often get away with bigger slices of pie.

I have written a lot about New Fuseki theory in Old Fuseki vs New Fuseki.

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Post #529 Posted: Mon Apr 01, 2019 10:51 am 
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Dear John,

I think that we are going to have to rethink our ideas of thickness and influence because of go AI. And other concepts, as well. :)

As for dividing the board diagonally, didn't you say that Sonoda sometimes does that?

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The Adkins Principle:

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— Winona Adkins

I think it's a great idea to talk during sex, as long as it's about snooker.

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Post #530 Posted: Mon Apr 01, 2019 12:31 pm 
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John Fairbairn wrote:
I have written a lot about New Fuseki theory in Old Fuseki vs New Fuseki.


$168.54 for a used copy from Amazon is just a bit too steep for me.

Edit: I now have found the thread on your book. Too bad it seems to be out of print.

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Post #531 Posted: Mon Apr 01, 2019 2:27 pm 
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Rank: UK 4 dan
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https://www.schaakengo.nl/goshop-keima/ ... -fairbairn
€10 plus postage

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Post #532 Posted: Mon Apr 01, 2019 2:42 pm 
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Uberdude wrote:
https://www.schaakengo.nl/goshop-keima/books/books-by-publisher/slate-and-shell/ss59-old-fuseki-vs-new-fuseki-fairbairn
€10 plus postage

Thanks!

Edit: I just discovered that the book is available from SmartGo, so I bought the electronic version. Which I can begin reading right now. ;-)

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Post #533 Posted: Mon Apr 01, 2019 4:00 pm 
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Very strange. In note #534 I wrote that White played :w30:, and when I go to edit it, that shows up, but in the note as it appears, it says that green played :w30:. Does the same thing happen here?

Edit: Yes, it does.

What about Black?

Edit: Black shows up as Purple.

Later edit: Corrected now. Thanks. :)

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 Post subject: Re: This 'n' that
Post #534 Posted: Sun Apr 07, 2019 9:15 pm 
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Direction of Play?

Basic diagram:

Click Here To Show Diagram Code
[go]$$Bc Play on the left side
$$ -------------------
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . O . . . .
$$ | . . O , . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . 2 . . . . . .
$$ | . . . . . . . . .
$$ | . . 1 , 3 . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . X , X . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ | . . . . . . . . .
$$ -------------------
$$ {AR 4:4 4:7}
$$ {AR 4:16 4:13}[/go]


Just about every opening textbook has a diagram like this. The arrows indicate the direction in which each enclosure naturally develops. If Black plays on the left side first, she can play on C-10 and then, if White plays on C-12, Black can jump to E-10, forming an ideal box framework.

Below are positions from actual pro games with enclosure facing enclosure on one side. The textbook play appears to be the extension to the 10-3 point. Is that where the pros actually played? And is there a better play?

Since the title has a question mark, you might think that there is a better play. ;) Anyway, food for thought. I'll reserve the next four posts for comments based upon the published Elf analysis.

Note that three of the games have no komi. In a no komi game the best practical play for White may be to make an overplay, an aggressive play, or to complicate the game. Conversely, Black may play safe, sound, and simple. Elf, OC, assumes a 7.5 komi.

Edit: It may come as no surprise that all the pros played the 10-3 extension, and that Elf preferred a different play in each case, to varying degrees. ;)

Click Here To Show Diagram Code
[go]$$Wc Takagawa (W) vs. Tainaka , 1952-04-09a
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , X . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

White to play. 4.5 komi.

Click Here To Show Diagram Code
[go]$$Wc Fujisawa Hideyuki (W) vs. Sakata, 1960-01-27a
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . . X . . . . |
$$ | . . O , . . . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . O , O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

White to play. No komi.

Click Here To Show Diagram Code
[go]$$Wc Cho Chikun (W) vs. Kono, 1970-06-17a
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . X . . . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . , O . . |
$$ | . . . . . . . . . . . . . . O . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

White to play. No komi.

Click Here To Show Diagram Code
[go]$$B Sugiuchi Kazuko (W) vs. Shirae Haruhiko, 1970-00-00aa
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . X O . . . . . O . . . . . . . . |
$$ | . . X , O . O . . , . . . . X , X . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . , X . . . . , . . . . . , O . . |
$$ | . . . X . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Black to play. No komi.

_________________
The Adkins Principle:

At some point, doesn't thinking have to go on?

— Winona Adkins

I think it's a great idea to talk during sex, as long as it's about snooker.

— Steve Davis


Last edited by Bill Spight on Tue Apr 09, 2019 6:41 pm, edited 4 times in total.
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 Post subject: Re: This 'n' that
Post #535 Posted: Sun Apr 07, 2019 10:34 pm 
Honinbo

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Click Here To Show Diagram Code
[go]$$Wc Takagawa (W) vs. Tainaka , 1952-04-09a
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , X . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

White to play. 4.5 komi.

Takagawa (of course, to those familiar with his play) took the C-10 point. Here are the next 10 plays.

Click Here To Show Diagram Code
[go]$$Wcm8 Moves 8 - 17
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . 2 . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . 0 . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 4 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 1 , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . 6 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . 8 X . . |
$$ | . . X , X . . . . , . . . . 3 , 7 9 . |
$$ | . . . . . . . . 5 . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:b9: extended on the top side, preventing a double wing formation by White. Play continued in a fairly standard way for the time.

----

Elf evaluated :w8: as losing 4%. But Elf's margin of error is around 4%, I think. It's high because Elf gives large error estimates, not because its winrate estimates are bad. So I think we can say that Elf considers :w8: to be questionable. To help us understand Elf's evaluation, let's compare Elf's main line after :w8: to its main line after :b7:.

Click Here To Show Diagram Code
[go]$$Bcm9 Main line after White 8, top attachment!
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 4 2 . . . . . . . . . . . . . . . |
$$ | . . W 1 . . . . . , . . . . . , . . . |
$$ | . . 3 5 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , X . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Elf thinks that :b9: should attach to the top of :w8: (marked)! :o After :b13: let's evaluate the left side. Maybe White has gained about 1 pt. of territory, 2 pts. of actual territory for White vs. 1 pt. of central influence for Black. Compare that with the next diagram.

Click Here To Show Diagram Code
[go]$$Wcm8 Textbook diagram
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 1 , 3 . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 2 . 4 . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , X . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


With this exchange, White's moyo has gained around 8 pts. more than Black's has. OC, moyo is not territory, so maybe White has gained about 3 pts. more than Black, a couple of more points than in Elf's main line diagram. ;)

Click Here To Show Diagram Code
[go]$$Wcm14 Main line after White 8, II
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . . . . . . |
$$ | . . O , . 4 . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O O . 5 . . . . . . . . . . . . . |
$$ | . . O X . . . . . , . . . . . , . . . |
$$ | . . X X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . 2 X . . |
$$ | . . X , X . . . . , . . . . . , 1 . . |
$$ | . . . . . . . . . . . . . 3 . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


White plays his preferred joseki in the bottom right. (Other bots might play the kosumi or keima.) Then Black plays the Go Seigen/AlphaGo shoulder blow, rather than an extension on the top side. (Well if Elf does not like the extension on the left side, why would it like one on the top side? ;))

:w18: surprised me. Since :b17: reduces the White moyo, why extend it? But AlphaGo, Elf, and other bots like the center. And this move nullifies Black's advantage there. (In particular it prevents a two step hane in the center. It also prevents Black E-13, threatening to connect either way.)

Click Here To Show Diagram Code
[go]$$Bcm19 Main line after White 8, III
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O 1 . . . . . . . 4 . . . . . |
$$ | . . O , 2 X . . . , . . . . . X . . . |
$$ | . . . . . 3 . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O O . O . . . . . . . . . . . . . |
$$ | . . O X . . . . . , . . . . . , . . . |
$$ | . . X X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . X X . . |
$$ | . . X , X . . . . , . . . . . , O . . |
$$ | . . . . . . . . . . . . . O . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:b19: and :b21: strengthen Black on the top side while still reducing the White moyo. Note that :w22: is an approach, not a wedge or pincer.

Now let's take a look at Elf's main line after :b7:.

Click Here To Show Diagram Code
[go]$$Wcm8 Main line after Black 7
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . X . . . |
$$ | . . a . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 4 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . 2 X . . |
$$ | . . X , X . . . . , . . . . . , 1 . . |
$$ | . . . . . . . . . . . . . 3 . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


White plays his preferred joseki in the bottom right corner. Then Black plays an ogeima enclosure in the top right, distantly approaching the bottom right stones. "a" is a rival with approximately the same win rate estimate, but "a" only gets 26k playouts to 51k playouts for the enclosure.

Click Here To Show Diagram Code
[go]$$Wcm12 Main line after Black 7, II
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . 2 . 1 . . . . . |
$$ | . . O , . . . . . , . . . . . X . . . |
$$ | . . c . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . a b . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . X X . . |
$$ | . . X , X . . . . , . . . . . , O . . |
$$ | . . . . . . . . . . . . . O . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:w12: approaches the top right corner. "a" and "b" have the same win rate estimates, but "a" gets only 17k playouts and "b" gets 5k playouts, while :w12: gets 22k playouts. Surely the left side extensions are playable at that point. :)

:b13: is a close pincer. "c" is a rival, but gets only 3k playouts versus 17k.

Click Here To Show Diagram Code
[go]$$Wcm14 Main line after Black 7, III
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O 3 . . . . . X . O . . . . . |
$$ | . . O , . 2 . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 1 , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . a . . . |
$$ | . . . . . . . . . . . . . . . . b . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . X X . . |
$$ | . . X , X . . . . , . . . . . , O . . |
$$ | . . . . . . . . . . . . . O . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:w14: finally makes the extension on the left side. The pincers "a" and "b" are rivals, with the same win rate estimates, but again it is a playout contest. "b" gets 3760 playouts and "a" gets 5230, while :w14: gets 5313, a very close call.

:b15: plays the shoulder hit and :w16: taps it underneath to contest the top side.

----

What seems to be going on is that Elf considers the extension for White to be premature at move 8, and perhaps prefers the attachment against the top left enclosure for Black. Perhaps it is an example of the dictum, corners before sides. Corners may remain urgent longer that we had thought. :)

And the top attachment against the White extension was an eye opener for me. It indicates that the extension may not be as large as the textbooks suggest.

Edit: Please note that the board in the actual game is rather more developed than in either of Elf's main lines.

_________________
The Adkins Principle:

At some point, doesn't thinking have to go on?

— Winona Adkins

I think it's a great idea to talk during sex, as long as it's about snooker.

— Steve Davis


Last edited by Bill Spight on Mon Apr 08, 2019 9:51 am, edited 10 times in total.

This post by Bill Spight was liked by: BlindGroup
Top
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 Post subject: Re: This 'n' that
Post #536 Posted: Sun Apr 07, 2019 10:35 pm 
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Posts: 8821
Liked others: 2602
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Click Here To Show Diagram Code
[go]$$Wc Fujisawa Hideyuki (W) vs. Sakata, 1960-01-27a
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . . X . . . . |
$$ | . . O , . . . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . O , O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

White to play. No komi.

Click Here To Show Diagram Code
[go]$$Wcm8 Moves 8 to 17
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 9 7 8 . . . . . . . . . . . . . |
$$ | . . . 5 X . . . 2 . . . . . X . . . . |
$$ | . . O , 6 . . . . , . . . . . , X . . |
$$ | . . . a . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 4 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , 1 . . |
$$ | . . . . . . . . . . . . . 0 . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . O , O . . |
$$ | . . . . . . . . . 3 . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Fujisawa Hideyuki (AKA Shuko) also played the 10-3 extension. The subsequent play has some notable features.

:b9: combined a 5 pt. extension from the enclosure with a 3 pt. extension from the Black stone in the top left corner. :w10: completed a double wing formation from the bottom left corner. When I was learning go, a double wing was supposed to be ideal, but pros, both at the time and historically, had not always rushed to prevent one. W"a" is a common response to the :b11: pincer, but Fujisawa chose to play a Kitani joseki, settling White into the corner. Then :b17: was a very high reduction of White's double wing, an unusual choice. Black may have been counting on the lack of komi to keep White from playing strongly against the reduction in exchange for a bit more territory.

----

Elf considers :w8: to be an 8% mistake, so it very probably is a mistake. As above, let's look at Elf's main line after :w8: and compare it with its main line after :b7:.

Click Here To Show Diagram Code
[go]$$Bcm9 Main line after White 8 (marked)
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . . X . . . . |
$$ | . . O 0 8 9 . . . , . . . . . , X . . |
$$ | . . . 2 3 . . . . . . . . . . . . . . |
$$ | . . 4 1 . . . . . . . . . . . . . . . |
$$ | . . 6 5 . . . . . . . . . . . . . . . |
$$ | . . . 7 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , W . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . O , O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Black plays the taisha in the top left corner. White takes territory in exchange for outside strength.

Click Here To Show Diagram Code
[go]$$Bcm19 Main line after White 8, II
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . . X . . . . |
$$ | . . O O O X 1 . . , . . . . . , X . . |
$$ | . . . O X . . . . . . . . . . . . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . 2 X . . . . . . . . . . . . . . . |
$$ | . . . 3 . . . . . . . . . . . . . . . |
$$ | . . 4 , . . . . . , . . . . . , O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . O , O . . |
$$ | . . . . . . . . . . . . 5 . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:b19: is a tesuji noted not long ago by John Fairbairn in human play in a different position. :) After :w22: Black retains sente and approaches the bottom right corner with :b23:. This approach to the high enclosure has a long pedigree.

Now let's look at Elf's main line after :b7:.

Click Here To Show Diagram Code
[go]$$Wcm8 Main line after Black 7
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . . X . . . . |
$$ | . . O , . . . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 1 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . 6 a . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . b . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 4 . . |
$$ | . . . . . . . . . . . . . . . 3 2 . . |
$$ | . . . X . . . . . , . . . . O , O 5 . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


As we may have anticipated, Elf considers the top left corner to be the hot spot of the board. :w8: is the now standard keima. Black turns to the right side, but starts with the outside attachment to White's bottom right enclosure. After that kikashi Black extends to the 10-4 point. Again, "a" has the same win rate estimate, but loses the playouts, 5k to 22k. To me that makes sense, because the high extension looks good with the rest of the board, and because of the Black stones in the bottom right, Black is not concerned about a White play at "b".

Click Here To Show Diagram Code
[go]$$Wcm14 Main line after Black 7, II
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . . X . . . . |
$$ | . . O , . . . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . 9 . b . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . a 8 X . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . . 2 X 6 . . . . , . . . . O , O O . |
$$ | . . 1 3 5 4 . . . . . . . . . . . . . |
$$ | . . . . . 7 . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:w14: invades the bottom left corner. Black takes sente and returns to the the bottom right with the turn, :b21:. :w22: is a tesuji aiming to play at "a" or "b". As is often the case, Elf ends its variation in media res, leaving us to wonder how Black will reply. ;)

My main takeaway is similar to the last example, The corner is hotter than the side, even one with facing enclosures. This corner, with the 3-5 Black stone on the side closer to the Black enclosure instead of the lone 4-4 stone, seems to be hotter than the one in the Takagawa game, perhaps because a Black wall would work better with the enclosure, so that Elf considers the side extension to be a worse mistake.

BTW, Elf considers :b9: in the actual game to be a 9-10% mistake, even worse than :w8:, returning the favor with interest. Both players, despite being among the world's best at the time, seemed to share an illusion about the value of those extensions, by comparison with a play in the top left corner.

_________________
The Adkins Principle:

At some point, doesn't thinking have to go on?

— Winona Adkins

I think it's a great idea to talk during sex, as long as it's about snooker.

— Steve Davis


Last edited by Bill Spight on Mon Apr 29, 2019 12:17 pm, edited 13 times in total.
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Post #537 Posted: Sun Apr 07, 2019 10:37 pm 
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{Under construction}

Click Here To Show Diagram Code
[go]$$Wc Cho Chikun (W) vs. Kono, 1970-06-17a
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . X . . . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . , O . . |
$$ | . . . . . . . . . . . . . . O . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

White to play. No komi.

Click Here To Show Diagram Code
[go]$$Wcm8 Moves 8 to 15
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . B . . . . |
$$ | . . 4 , 6 . . . . , . . . . . , X . . |
$$ | . . 2 O . . . . . . . . . . . . . . . |
$$ | . . 3 5 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 8 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 7 , . . . . . , . . . . . , 1 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . , . . . . . , O . . |
$$ | . . . . . . . . . . . . . . O . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Cho Chikun also played the 10-3 extension. Then Kono played the usual underneath attachment in the top left corner. The :b13: kosumi was standard when Black also had a strong, low stone to the right ( :bc: ), to provide a high-low balance. :b15: was the standard blocking extension on the right side.

Click Here To Show Diagram Code
[go]$$Wcm16 Moves 16 to 21
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . X . . . . |
$$ | . . X , X . . . . , . . . . . , X . . |
$$ | . . X O . . . . . . . . . . . . . . . |
$$ | . . O O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . , O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 6 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 2 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . 3 . . . . . , O 4 . |
$$ | . . . . . 1 . . . . . . . . O . 5 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Cho approached the bottom left corner and then made a double wing formation with :w18: :b19: was a probe in the corner, and after :w20: pulled back, Kono played the invasion at :b21:.

{More analysis to follow.}

_________________
The Adkins Principle:

At some point, doesn't thinking have to go on?

— Winona Adkins

I think it's a great idea to talk during sex, as long as it's about snooker.

— Steve Davis


Last edited by Bill Spight on Mon Apr 29, 2019 12:19 pm, edited 5 times in total.
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Post #538 Posted: Sun Apr 07, 2019 10:41 pm 
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{Under construction}

Click Here To Show Diagram Code
[go]$$B Sugiuchi Kazuko (W) vs. Shirae Haruhiko, 1970-00-00aa
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . X O . . . . . O . . . . . . . . |
$$ | . . X , O . O . . , . . . . X , X . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . , X . . . . , . . . . . , O . . |
$$ | . . . X . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Black to play. No komi.

Click Here To Show Diagram Code
[go]$$B Moves 17 to 19
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . X O . . . . . O . . . . . . . . |
$$ | . . X , O . O . . , . . . . X , X . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , 1 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 3 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . , X . . . . , . . . . . , O . . |
$$ | . . . X . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Shirae also played the 10-3 extension with :b17:. Sugiuchi (still active at age 92, see the Sugiuchi watch thread, viewtopic.php?p=241376#p241376 ) replied with :w18:, the standard checking extension on the right, only a two space extension because of the weakness of the ogeima enclosure. Black then pincered on the left side, and the battle continued there for several moves.

{More analysis to follow.}

_________________
The Adkins Principle:

At some point, doesn't thinking have to go on?

— Winona Adkins

I think it's a great idea to talk during sex, as long as it's about snooker.

— Steve Davis

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Post #539 Posted: Mon Apr 08, 2019 3:09 am 
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Hi Bill,

Curious about a low-end bot's evals.
Takagawa-Tainaka:
Sakata-Fujisawa:
Cho-Kono (small typo in #534's date: '1907' )
Sugiuchi-Shirae:
Hunch: the bot isn't crazy about the "big-wedge/shared point/extension".
However, even top pros occasionally botch their 90+% winrates (dropping to 50% in 1 move, say); and a bot can keep its 90% winrate with a 0.5 lead; so anything that's within 5% is totally playable for most mere mortals... :blackeye: ... big wedge-extension or otherwise.
( Just don't let the 5% repeatedly spiral down over 20 moves. )


This post by EdLee was liked by: Bill Spight
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Post #540 Posted: Mon Apr 08, 2019 4:45 am 
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EdLee wrote:
Curious about a low-end bot's evals.


Interesting. :) Since Deep Leela was trained on human play, I thought that it would agree with a human at least once. ;)

Quote:
Cho-Kono (small typo in #534's date: '1907' )


My bad. ;) OTOH, the spell checker changed Cho's name to Cho Chicken. :lol:

_________________
The Adkins Principle:

At some point, doesn't thinking have to go on?

— Winona Adkins

I think it's a great idea to talk during sex, as long as it's about snooker.

— Steve Davis

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