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 Post subject: How is your positional judgement? Game 21
Post #1 Posted: Wed Nov 13, 2019 12:21 pm 
Honinbo

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Game 21

As usual, we assume area scoring with 7½ pt. komi.

After :b31: Elf estimates a winrate of 91½% for one player. Which player is it?

Click Here To Show Diagram Code
[go]$$Bc White to play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . O . O . . |
$$ | . . . , . . . . . , . . . . . , X X . |
$$ | . . . . . . . . . . . . . . . O X O . |
$$ | . . . . . . . . . . . . . . . O O X . |
$$ | . . . . . . . . . . . . . . . O X X . |
$$ | . . . . . . . . . . . . . . O O X . . |
$$ | . . . . . . . . . . . . . X O X . . . |
$$ | . . . , . . . . . , . . . O X , . . . |
$$ | . . . . . . . . . . . . . O X . . . . |
$$ | . . . . . . . . . . . . O X . . . . . |
$$ | . . . . . . . . . . . . X . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . O . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Enjoy! :D

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 Post subject: Re: How is your positional judgement? Game 21
Post #2 Posted: Wed Nov 13, 2019 2:44 pm 
Lives with ko

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My first instinct: White white white. It looks so much more active and white has the hugely important sente. B's side is pretty big, though, and the variations I'm reading aren't very clear. This one is particularly interesting, because I feel like I can play out the whole game so far.
Click Here To Show Diagram Code
[go]$$Bc Who knows for the first 7 moves
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . 2 . . . . . . . . . 6 . . . . |
$$ | . . . , . . . . . , . . . . . , 1 . . |
$$ | . . . . . . . . . . . . . . . 8 9 . . |
$$ | . . . . . . . . . . . . . . . 0 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 7 . . |
$$ | . . 5 , . . . . . , . . . . . , . . . |
$$ | . . . . 4 . . . . . . . . . . 3 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Not sure on who took which corner first but almost no doubt that this was the position after move 10. So far I would guess 50/50 or B slightly ahead.
Click Here To Show Diagram Code
[go]$$Bc Order might be a little different
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . O . . . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . O X 0 . |
$$ | . . . . . . . . . . . . . . . O 8 9 . |
$$ | . . . . . . . . . . . . . . . 2 1 . . |
$$ | . . . . . . . . . . . . . . . 4 3 . . |
$$ | . . . . . . . . . . . . . . 6 5 . . . |
$$ | . . . , . . . . . , . . . . 7 , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . O . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


W's moves all look ok, so certainly not more than 65% for B yet. Actually, I thought that B wasn't supposed to allow W to get this cut and take the corner like they did in game. Is W is already winning? My joseki knowledge is kyu-level.

Click Here To Show Diagram Code
[go]$$Bc End at the double hane.
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . O . 2 . . |
$$ | . . . , . . . . . , . . . . . , X 5 . |
$$ | . . . . . . . . . . . . . . . O X O . |
$$ | . . . . . . . . . . . . . . . O O X . |
$$ | . . . . . . . . . . . . . . . O X 1 . |
$$ | . . . . . . . . . . . . . . 4 O X . . |
$$ | . . . . . . . . . . . . . 3 O X . . . |
$$ | . . . , . . . . . , . . . 6 X , . . . |
$$ | . . . . . . . . . . . . . 8 7 . . . . |
$$ | . . . . . . . . . . . . 0 9 . . . . . |
$$ | . . . . . . . . . . . . B . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . O . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


This is where the big swings happen, so let's look closely. The exchange of 3 for 4 isn't too shabby for B, but in the corner B wishes they didn't have to play 1 and 5 protecting the same cut, rather move 1 down a few lines. I approve of 6 and 7. 8 is maybe a little aggressive, instinct tells me to try to ladder or loosely net 3 instead, but I can see why 8 might be better than those. 9 is the logical response. 10 is the reasonable continuation, since B has so many weaknesses nearby, but B's double hane seems to work really well. You'd think that W should win with double atari, but B's plan is to sacrifice the one stone to capture the middle stones in a ladder.
Click Here To Show Diagram Code
[go]$$Wm32 White to play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . O . O . . |
$$ | . . . , . . . . . , . . . . . , X X . |
$$ | . . . . . . . . . . . . . . . O X O . |
$$ | . . . . . . . . . . . . . . . O O X . |
$$ | . . . . . . . . . . . . . . . O X X . |
$$ | . . . . . . . . . . . . . . O O X . . |
$$ | . . . . . . . . . . . . . X O X 5 . . |
$$ | . . . , . . . . . , . . 6 O X 3 . . . |
$$ | . . . . . . . . . . . . . O X 4 . . . |
$$ | . . . . . . . . . . . . O X 1 . . . . |
$$ | . . . . . . . . . . . . X 2 . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . O . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

This instinctually should be disaster for W - but actually on evaluation even this doesn't look THAT bad. Thus when W plays a more modest move:
Click Here To Show Diagram Code
[go]$$Wm32 White to play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . O . O . . |
$$ | . . . , . . . . . , . . . . . , X X . |
$$ | . . . . . . . . . . . . . . . O X O . |
$$ | . . . . . . . . . . . . . . . O O X . |
$$ | . . . . . . . . . . . . . . . O X X . |
$$ | . . . . . . . . . . . . . . O O X . . |
$$ | . . . . . . . . . . . . . X O X . . . |
$$ | . . . , . . . . . , . . . O X , . . . |
$$ | . . . . . . . . . . . . . O X . . . . |
$$ | . . . . . . . . . . . 1 O X 2 . . . . |
$$ | . . . . . . . . . . . . X . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . O . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

I'd expect W to be far ahead. The only moves I see that could be big mistakes seem to be B's, other than W's aggression 28 and 30, but it's hard to convince myself that those are such horrid mistakes. So I'm going to go with my first instinct, but I'm actually really eager to see the AI analysis of this one.

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 Post subject: Re: How is your positional judgement? Game 21
Post #3 Posted: Wed Nov 13, 2019 3:34 pm 
Gosei

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My ten-second opinion is Black; knowing modern AI play, it's just too easy for me to imagine Black scooping out all the territory at the top and White not being able to make it up.

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 Post subject: Re: How is your positional judgement? Game 21
Post #4 Posted: Wed Nov 13, 2019 3:57 pm 
Judan

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Someone has made order mistakes in this joseki variation.


This post by Uberdude was liked by: Bill Spight
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 Post subject: Re: How is your positional judgement? Game 21
Post #5 Posted: Wed Nov 13, 2019 4:26 pm 
Gosei
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My no-LZ analysis favors Black


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 Post subject: Re: How is your positional judgement? Game 21
Post #6 Posted: Wed Nov 13, 2019 4:32 pm 
Lives with ko

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I'm worried about the double atari white has, but by the meta-argument of "a pro wouldn't have missed that", it's probably not as worrying for black as I thought at first. It would probably be a trade of white ruining black's territory while black ruin white's wall.

Then, white has pushed from behind and been hane-ed repeatedly. The white chain at Q15 is a bit short of liberty and at the very least black can get forcing move taking advantage with that. Which means that getting something living on wide open top side shouldn't be hard for black. Thus, white wall looks scary, but it's only that, look. Still if black invade white can expect some of the center in exchange but reducing the center shouldn't be hard, and black can get a lot of territory on the side.

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Post #7 Posted: Wed Nov 13, 2019 5:32 pm 
Gosei

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White should have sticked to its initial plan. I definitly imagine myself commiting the same mistake. White decided to put more weight on a general rule and did not acknowledge the concrete position enough. Lost a game today myself in a similar way, although I did not wrongly prevent a "ponuki". In my case it was the general rule "connecting" that stopped me from playing the proper move. Both in this game and in my game the efficiency of the "general rule" move and the "practical" move was not evaluated correctly by the failing players. In any case my blunder was much bigger than the pros, about 10 versus 5 points :). (Intuition should have trumped formal knowledge, perhaps I learn to trust my intuition even more versus formal knowledge in cases where actual counting seems too difficult for me.)


Click Here To Show Diagram Code
[go]$$Wc White to play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . O . . . . . . . . X . . . . |
$$ | . X . O . . . . . O . . . . . , X X . |
$$ | . . . . . . . . . . . . . . . X O O . |
$$ | . . X . . . . . . . . . . X X X . . . |
$$ | . . X . . . . . . . . . X . X O O . . |
$$ | . X O O . . . . . . . . . X O . . . . |
$$ | . . X O . . . . . . . . . . O . . . . |
$$ | . . X O . . . . . , . . . . . , . . . |
$$ | . . X O . . . . . . . . . . . . . . . |
$$ | . . . X O . . . . . . . . . . . O . . |
$$ | . . . X O . . . . . . . . . . O . O . |
$$ | . . . X O . . . . . . . . . O . O X . |
$$ | . . . X a . . . . . . . . X X O O X . |
$$ | . . b O . . . . . , . . . X O X . X . |
$$ | . . . . . O . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


After I evaluated the white double hane stone at C3 will survive, I was wrongly satisfied with white connecting at a and dismissed the clearly superior white b.

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Post #8 Posted: Thu Nov 14, 2019 2:05 am 
Lives with ko

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This game looks vaguely familiar, but I can't recollect from where. It feels like white knows what he's doing, so white should be ahead. I'd probably play at a next to fix the shape and black has to take care of his cutting points so that white keeps sente.

Click Here To Show Diagram Code
[go]$$Bc White to play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . O . O . . |
$$ | . . . , . . . . . , . . . . . , X X . |
$$ | . . . . . . . . . . . . . . . O X O . |
$$ | . . . . . . . . . . . . . . . O O X . |
$$ | . . . . . . . . . . . . . . . O X X . |
$$ | . . . . . . . . . . . . . . O O X . . |
$$ | . . . . . . . . . . . . . X O X . . . |
$$ | . . . , . . . . . , . . . O X , . . . |
$$ | . . . . . . . . . . . a . O X . . . . |
$$ | . . . . . . . . . . . . O X . . . . . |
$$ | . . . . . . . . . . . . X . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . O . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

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Post #9 Posted: Thu Nov 14, 2019 5:08 am 
Gosei
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LZ analysis - confirms my no-LZ analysis but with a very interesting main line


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 Post subject: Re: How is your positional judgement? Game 21
Post #10 Posted: Thu Nov 14, 2019 2:04 pm 
Honinbo

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I like white

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be immersed

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Post #11 Posted: Sat Nov 16, 2019 10:43 am 
Dies in gote

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Bill - Thank you for winding the clock back for me! I was just getting into Go in the mid 1960s and I bought the 3 volume Nihon Kiin Fundamental Series in the summer of 19xx and they sent me a free copy of Kido which included this game. I can still name the players, year and round of this title match after some 52 years. A very similar opening occurred two games later of course in that match.

Its the 1967 Honinbo Title Match Game 3 between Sakata (White) and Rin.


Best Wishes - John

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Post #12 Posted: Sat Nov 16, 2019 11:05 am 
Honinbo

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John Tilley wrote:
Bill - Thank you for winding the clock back for me! I was just getting into Go in the mid 1960s and I bought the 3 volume Nihon Kiin Fundamental Series in the summer of 19xx and they sent me a free copy of Kido which included this game. I can still name the players, year and round of this title match after some 52 years. A very similar opening occurred two games later of course in that match.

Its the 1967 Honinbo Title Match Game 3 between Sakata (White) and Rin.


Best Wishes - John


This game made a big impression on me. :) I forget when I first saw it. I wasn't ready for Kido, when I was in Japan. Igo Club was more my speed. I remember that someone took me up to meet the editor of Go World in the Chuo Kaikan. I'm pretty sure it wasn't Bozulich. Maybe Dowsey or you?

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Post #13 Posted: Sun Nov 17, 2019 11:45 am 
Dies in gote

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Bill's starting position after Black 31 with an advantage of 91.6% to one player is fascinating, however in the actual match there must have been a lot of stress and doubt for Black. White has pressed down and is building on a grand scale and Black must have had some serious doubts. I am sure Bill will do a summary of this game eventually, but note it gets top billing for White in a selection of his games published in 1970 - 24 pages, 18 figures and 44 explanatory diagrams.

In real life facing some opponents across the board must be really tough, because of their reputation. No names in the "Hide" button - just their respective ages.

White was 47 years old, a 9 dan and "one of the pre-eminent geniuses of Go history" <to quote Bozulich>, Black was just 25 years old.


Hopefully we will see some more AI analysis.

Bill - I think you meant to say that either I or Stuart Dowsey introduced you to Mr Yosida, who was editor of the English language magazine "Go Monthly Review".

John Tilley

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Post #14 Posted: Sun Nov 17, 2019 1:53 pm 
Honinbo

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John Tilley wrote:
Hopefully we will see some more AI analysis.


Oh, you bet! :)

Quote:
Bill - I think you meant to say that either I or Stuart Dowsey introduced you to Mr Yosida, who was editor of the English language magazine "Go Monthly Review".

John Tilley


Thanks, I had forgotten Yosida's name, as well as the magazine's. ;) The memory came back to me when I read your note. IIRC, one of you took me upstairs at the Kiin to meet him. He gave me a complimentary copy of Go Monthly Review. I didn't subscribe to it, but I did take Igo Kurabu. Later I subscribed to Kido, which I till miss.

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Post #15 Posted: Sun Dec 08, 2019 12:03 am 
Lives in gote

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A bit late to the party here (so many other interesting conversations on this board over the past two weeks!), but since the official solution hasn't been posted yet, I'll hazard my own guess before peeking at others'.

So my first impression is that white's influence at the top looks huge, whereas black is relatively confined. But then (still glancing at the position without reading), black's area looks more like cash in the bank, while white's wall has a few cutting points so it isn't really that thick. But once I start to read out specific moves, it looks like black has more than enough weak spots too. White P8 for example could do a fair bit of damage. If both sides get cut to ribbons, I think black stands to lose more.

So all up, I prefer white.

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Post #16 Posted: Sun Dec 08, 2019 3:34 pm 
Honinbo

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Discussion of the Elf commentary

After :b31: Elf estimates a winrate of 91½% for one player. Which player is it?

Black.

But White won by resignation.

Click Here To Show Diagram Code
[go]$$Bcm31 Black is ahead
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . O . O . . |
$$ | . . . , . . . . . , . . . . . , X X . |
$$ | . . . . . . . . . . . . . . . O X O . |
$$ | . . . . . . . . . . . . . . . O O X . |
$$ | . . . . . . . . . . . . . . . O X X . |
$$ | . . . . . . . . . . . . . . O O X . . |
$$ | . . . . . . . . . . . . . X O X . . . |
$$ | . . . , . . . . . , . . . O X , . . . |
$$ | . . . . . . . . . . . . . O X . . . . |
$$ | . . . . . . . . . . . . O X a . . . . |
$$ | . . . . . . . . . . . . 1 . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . O . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


This game is GoGoD 1967-05-23a, the third game of the 22d Honinbo final between Sakata Eio (W) and Rin Kaiho (Lin Haifeng).

First, let me note that this game could be in the Beat Elf! thread ( https://lifein19x19.com/viewtopic.php?f=15&t=16641 ). Elf's first choice for :b31: is at a, but then it awards Lin's two step hane an 8% higher winrate, even though Lin's play was almost entirely off of Elf's radar, with only one rollout.

Elf's recommended continuation

Click Here To Show Diagram Code
[go]$$Wcm32 Elf's continuation
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . O . O . . |
$$ | . . . , . . . . . , . . . . 9 8 X X . |
$$ | . . . . . . . . . . . . . . . O X O . |
$$ | . . . . . . . . . . . . . . . O O X . |
$$ | . . . . . . . . . . . . . . . O X X . |
$$ | . . . . . . . . . . . . . . O O X . . |
$$ | . . . . . . . . . . . . . X O X . . . |
$$ | . . . , . . . . . , . . . O X , . . . |
$$ | . . . . . . . . . . . . . O X . . . . |
$$ | . . . . . . . . . . . 1 O X 2 . . . . |
$$ | . . . . . . . . . . . 3 X . . . . . . |
$$ | . . . . . . . . . . 5 4 6 . . . . . . |
$$ | . . . . . . . . . . 7 . . . . . X . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . O . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


White extends, Black connects, then White turns and Black plays another two step hane. The descent, :w38:, is big. After :w40: the rollouts drop below 1500, so Elf's variation ends. I anticipate a reduction of White's huge sphere of influence.

Earlier in the game

The record of this game made a big impression on me as a kyu player. I was familiar with the joseki in the top right corner, but not with it carried out to this extent. I remember thinking, My God, do I have to learn all of this? ;)

There are two standout errors in the play, according to Elf. The first is :b23:.

Click Here To Show Diagram Code
[go]$$Bcm23 :b23: loses 14% to par
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . O . O . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . O X O . |
$$ | . . . . . . . . . . . . . . . O O X . |
$$ | . . . . . . . . . . . . . . . O X X . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . . . . . . . . . . . . . 1 O X . . . |
$$ | . . . , . . . . . , . . . . X , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . O . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


This move is a mistake? :shock: Why, doesn't it force White to make an empty triangle? Yes, it leaves a few cutting points, but Black can protect.

Elf's recommended variation

Click Here To Show Diagram Code
[go]$$Bcm23 Elf's mainline variation
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . O . O . . |
$$ | . . . , . . . . . , . . . . . , X 1 . |
$$ | . . . . . . . . . . . . . . . O X W . |
$$ | . . . . . . . . . . . . . . . O O X . |
$$ | . . . . . . . . . . . . . . . O X X . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . . . . . . . . . . . . . 4 O X 3 . . |
$$ | . . . , . . . . . , . . . . X 2 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . O . 5 . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Elf recommends capturing the :wc: stone in the top right corner, and, after :w24: - :w26:, the one space pincer, :b27:, which also serves as a ladder breaker.

Sakata's blunder

Click Here To Show Diagram Code
[go]$$Wcm24 :w24: is a blunder, losing 28½% to par
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . O . O . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . O X O . |
$$ | . . . . . . . . . . . . . . . O O X . |
$$ | . . . . . . . . . . . . . . . O X X . |
$$ | . . . . . . . . . . . . . . 1 O X . . |
$$ | . . . . . . . . . . . . . X O X . . . |
$$ | . . . , . . . . . , . . . . X , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . O . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Surely you jest. :shock: :-?

OK, what does Elf recommend?

Click Here To Show Diagram Code
[go]$$Wcm24 Elf's mainline variation
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 4 . O . . . . . . . . . O . O . . |
$$ | . . . , . . . . . , . . . . . , X 1 . |
$$ | . . . . . . . . . . . . . . . O X O . |
$$ | . . . . . . . . . . . . . . . O O X . |
$$ | . . . . . . . . . . . . . . . O X X . |
$$ | . . . . . . . . . . . . . . 2 O X . . |
$$ | . . . . . . . . . . . . . X O X . . . |
$$ | . . . , . . . . . , . . . . X , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , . . . . . , 3 . . . . , . . . |
$$ | . . . . O . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Isn't :b25: worth 30 points, versus that measly corner? OC, :w26: checks Black's expansion on the bottom side. Then :b27: invades the top left corner.

I don't make the news, folks, I just report it. Explaining all this is above my pay scale. That's twice this game has made a big impression on me. ;)

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

My two main guides in life:
My mother and my wife. :)

Everything with love. Stay safe.

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 Post subject: Re: How is your positional judgement? Game 21
Post #17 Posted: Sun Dec 08, 2019 5:26 pm 
Judan

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I think one key factor why the ponnuki isn't great for black and white is happy to trade is the fact White didn't yet make the Q10 r11 exchange. White can later peep at that cutting point to get 1 in sente to help with a possible invasion. R10 is obviously a far better place to have a white stone than Q10 given black has one at r11. The s11 peep is another way to use the cut weakness.

Click Here To Show Diagram Code
[go]$$Wc later invasion aji
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . O . . . . . . . . . O . O . . |
$$ | . . . , . . . . . , . . . . . , X O . |
$$ | . . . . . . . . . . . . . . . O X O . |
$$ | . . . . . . . . . . . . . . . O O X . |
$$ | . . . . . . . . . . . . . . . O X X . |
$$ | . . . . . . . . . . . . . . X O X . . |
$$ | . . . . . . . . . . . . . X . X 2 . . |
$$ | . . . , . . . . . , . . . . X , 1 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 3 . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , . . . . . , O . . . . , . . . |
$$ | . . . . O . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


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 Post subject: Re: How is your positional judgement? Game 21
Post #18 Posted: Mon Dec 09, 2019 12:07 pm 
Honinbo

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Since Elf admits to misevaluating :b31:, because Lin's move was better, I expect that it misevaluated earlier plays as well. It did not prefer :w28:, but it did not, I guess, give it a low enough winrate. I now think that it should have said that it loses 9% to par. Here is it's recommended play, instead. :)

Click Here To Show Diagram Code
[go]$$Wcm28 Elf's mainline for :w28:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . W . 0 . . . . . O . O . . |
$$ | . . . , . . . . . , . . . . 3 2 X X . |
$$ | . . . . . . . . . . . . . . . O X O . |
$$ | . . . . . . . . . . . . . . . O O X . |
$$ | . . . . . . . . . . . . . . . O X X . |
$$ | . . . . . . . . . . . . . . O O X . . |
$$ | . . . . . . . . . . . . 9 X O X 4 . . |
$$ | . . . , . . . . . , . . . O X 1 . . . |
$$ | . . . . . . . . . . . . . 5 X . . . . |
$$ | . . . . . . . . . . . . . 7 6 . . . . |
$$ | . . . . . . . . . . . . . . 8 . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . O . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

:wc: = :w38:

:w28: plays the atari right away. :b29: plays kikashi before connecting. Then, with :w28: in place, Black does not hane at the head of :w32: or :w34:, but simply extends. :b37: is a wedge to reduce the influence of White's wall. :w38: attacks :b37:, making a small base at the same time.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

My two main guides in life:
My mother and my wife. :)

Everything with love. Stay safe.

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 Post subject: Re: How is your positional judgement? Game 21
Post #19 Posted: Fri Dec 20, 2019 11:56 am 
Dies in gote

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Rin had beaten Sakata in the 1965 Meijin and kept the title in 1966 and 1967, so Rin's first Honinbo challenge in 1967 was something special.

It fascinated me at the time that Sakata playing White used the sequence in the top right corner in this game and then again in Game 5. The first time he played it, it must have put a lot of pressure on Rin and Sakata won. When Sakata played it again I was stunned, I would love to know what Rin thought. Rin lost Game 5 btw and Sakata kept his Honinbo title.

I suspect that if AI had been around then, Sakata would still have played as he did in Game 5 - he would have valued the psychological pressure more than that AI % win rate.

Attachment:
Sakata - Rin 1967 Honinbo - Game 3-medium.jpg
Sakata - Rin 1967 Honinbo - Game 3-medium.jpg [ 190.65 KiB | Viewed 1741 times ]


The photo shows Game 3 - Sakata on the right, Rin on left. Takagawa is watching, with Murakami Bunsho (Amateur Honinbo) to the left of Takagawa. I spoke to Murakami in 1970 about Sakata, he said he couldn't win an even game but had a chance on 2 stones.

As I said in a previous post - this game is the highlight game in a two volume collection of Sakata's games, the other four games from the 22nd Hononbo also feature.

Never a dull moment.

John


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