How is your positional judgement? Game 21

Bill Spight · #1

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!

TelegraphGo · #2

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.

dfan · #3

Uberdude · #4

Someone has made order mistakes in this joseki variation.

Knotwilg · #5

Bki · #6

Gomoto · #7

bayu · #8

Knotwilg · #9

LZ analysis - confirms my no-LZ analysis but with a very interesting main line

Kirby · **#10**

John Tilley · **#11**

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.

Best Wishes - John

Bill Spight · **#12**

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.

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?

John Tilley · **#13**

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.

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

Bill Spight · **#14**

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.

xela · **#15**

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'.

Bill Spight · **#16**

Discussion of the Elf commentary

Uberdude · **#17**

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]

Bill Spight · **#18**

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]$$Wcm28 Elf's mainline for $$ --------------------------------------- $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . . . . . . . . . . . . . . . . | $$ | . . . . O . W . 0 . . . . . O . O . . | $$ | . . . , . . . . . , . . . . 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]

=

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

, but simply extends. :b37:

is a wedge to reduce the influence of White's wall. :w38:

attacks

, making a small base at the same time.

John Tilley · **#19**

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 [ 190.65 KiB | Viewed 11498 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

dhu163 · **#20**

Surprising. And useful as this is a fairly standard fuseki shape that I've seen (once) even in recent katago self-play.

How is your positional judgement? Game 21

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