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 Post subject: Re: How is your positional judgement?
Post #121 Posted: Thu Oct 24, 2019 1:42 am 
Judan

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TelegraphGo wrote:
Admittedly, I don't know just how lopsided Elf likes to evaluate, but my impression is that passing (basically what playing L2 is) would drop you from 50% to maybe 80%

Elfv2 (which I think is what was used for the historical analysis Bill is using, but not sure) is way more extreme than that, a pass for the first move gives white >98.5%. From a 50-50 position, a 10% change is maybe a 1 point mistake. (80->90% is probably more than 1 point). So when Bill is posting these ~90% games, that's about a 5 point lead to my mind (which is a pretty terrible opening for a pro after <50 moves, but it's not 20!). Indeed for game 12 which Elf gave black 96½%, Tryss showed KataGo thought it was a 7.8 point lead and 68%.

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Post #122 Posted: Thu Oct 24, 2019 3:15 am 
Gosei
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Interesting and confusing: in my Lizzie 007 interface, LZ network and Kata network disagree who's ahead in Game 16. Anyone else has noticed that in their environment?

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Post #123 Posted: Thu Oct 24, 2019 3:26 am 
Judan

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Possibly because KataGo read the 0 komi of your sgf whilst LZ assumed 7.5?

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Post #124 Posted: Thu Oct 24, 2019 4:05 am 
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Probably, because my Katago agree with your LZ

Edit : yup, if you put 0.0 komi, you get your result, but if you change the komi to 7.5, you go back to 77%wr

What's interesting is that with 7.5 komi, Katago think white score is +10, while with 0 komi, it's -1, a difference of 11 points !

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Post #125 Posted: Thu Oct 24, 2019 4:24 am 
Gosei
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Uberdude wrote:
Possibly because KataGo read the 0 komi of your sgf whilst LZ assumed 7.5?


Yes, that seems to be the case. So this is structural? Kata reads the komi stored in the sgf and LZ doesn't, making an assumption of 7,5?

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Post #126 Posted: Thu Oct 24, 2019 4:42 am 
Gosei

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To be pedantic, it's Lizzie that reads the SGF. It certainly tells the komi to KataGo; I'm not sure whether it also tells it to Leela Zero (it's just a GTP command), but it doesn't really matter, since Leela Zero can't do anything with the information, as it has the assumption built in that komi is inherently 7.5. The komi is baked into the Leela Zero (and AlphaZero) model, while KataGo is more flexible (time for some more huzzahs for lightvector!).


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Post #127 Posted: Thu Oct 24, 2019 6:32 am 
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LZ-Kata analysis (komi 7,5)



Meta-analysis: I've been participating since game 2 and I'm right-wrong 11-4
"Dwyrin's heuristic" (as coined by me up here) is right-wrong 9-3 and 4 times doesn't apply.


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Post #128 Posted: Thu Oct 24, 2019 9:42 am 
Honinbo

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Uberdude wrote:
TelegraphGo wrote:
Admittedly, I don't know just how lopsided Elf likes to evaluate, but my impression is that passing (basically what playing L2 is) would drop you from 50% to maybe 80%

Elfv2 (which I think is what was used for the historical analysis Bill is using, but not sure) is way more extreme than that, a pass for the first move gives white >98.5%.


Well, the cat's out of the bag, so I'm not hiding this.

TelegraphGo's impression is uncannily accurate. According to Elf, accepting the bad shape lost Black 30% to par.

A pass for the first move has an expected cost of approximately 14 pts. OC, the relation between winrates and points is not linear, but it's not too far off until the winrate approaches 0 or 1. A linear relationship would suggest around a 3% difference for each point on the board (48/14). That's actually close to what statistics on Japanese pro games from the 1970s suggested for komi differences. :)

I am using the published Elf commentaries of GoGoD games. The analyses were done in October, 2018, according to the dates on the SGF files. I thought that Elf v2 came out later than that.

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Post #129 Posted: Thu Oct 24, 2019 11:35 am 
Honinbo

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Is elf less useful with such aggressive swings?

Might as well just have a bit that says “White win” or “Black win”, rather than a percentage or point evaluation..

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Post #130 Posted: Thu Oct 24, 2019 12:48 pm 
Honinbo

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Kirby wrote:
Is elf less useful with such aggressive swings?

Might as well just have a bit that says “White win” or “Black win”, rather than a percentage or point evaluation..


Well, with the Elf commentaries, which use a humungous number of playouts, I like the added precision of the larger swings when evaluating specific plays. :) Precision is not the same thing as accuracy, OC. ;) And for these positions, I think that the difference between an 85% winrate estimate and a 90% estimate is meaningful.

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Post #131 Posted: Thu Oct 24, 2019 1:35 pm 
Honinbo

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Good point.. I suppose similar reasoning gives the only reason I consider Fahrenheit worth considering at all as a measurement of heat. Overall, I like Celsius better, but the difference in temperature is easier to express more precisely with whole numbers in Fahrenheit :-p

I’d still choose Celsius, though.

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Post #132 Posted: Thu Oct 24, 2019 3:22 pm 
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Kirby wrote:
I’d still choose Celsius, though.


Celsius 233, good book. ;)

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Post #133 Posted: Thu Oct 24, 2019 10:39 pm 
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My discussion of Elf's commentary for Game 14.

Game 14

Kiyonari Tetsuya, 9 dan (W) vs. Takemiya Masaki, 9 dan, 1998-00-00aj.

After :w34: Elf estimates White's winrate as 91% (24.4k playouts), inherited from Elf's choice of reply. (I try to have the last play the same as Elf's top choice, but that was impossible in this game.) However, Black, Takemiya, won by 3½ pts.

Click Here To Show Diagram Code
[go]$$Wcm34 White is ahead.
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . O . X O . . |
$$ | . . . , . . . . . X . . . . . X O . . |
$$ | . . O . X . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . O . . . . . . . . . . . X O X . |
$$ | . . . . . X . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . , . . . . . , . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . X . . . . . . X . . . . |
$$ | . . . O . . O O . X . . . . . X . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Elf's recommended continuation for :b35:

Click Here To Show Diagram Code
[go]$$Bcm35 Elf's mainline for :b35:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . 0 . . 2 . 8 . . . . . . . . . . . . |
$$ | . 9 6 O 1 4 . . . . . . . O . X O . . |
$$ | . . 7 3 5 . . . . X . . . . . X O . . |
$$ | . . O . X . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . O . . . . . . . . . . . X O X . |
$$ | . . . . . X . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . , . . . . . , . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . X . . . . . . X . . . . |
$$ | . . . O . . O O . X . . . . . X . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Black plays the jump attachment on the third line and then intrudes into the top left corner. White prefers to let Black in instead of letting Black make a territorial moyo on the top side.

Click Here To Show Diagram Code
[go]$$Bcm45 Elf's mainline for :b35:, continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . O . . O . O . . . . . . . . . . . . |
$$ | 2 X O O X O . . . . . . . O . X O . . |
$$ | . 3 X X X . . . . X . . . . . X O . . |
$$ | . 1 O . X . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . O . . . . . . . . . . . X O X . |
$$ | . . . . . X . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . , . . . . . , . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . 5 X O . |
$$ | . . . . . . . . . . . . . . . . 4 . . |
$$ | . . . . . . . . . . . . . . . . . 6 . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . X . . . . . . X . . . . |
$$ | . . . O . . O O . X . . . . . X . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Next, White expands his territory on the right side into the bottom right, preventing Black's kikashi against the White group.

Both of these variations have been lurking for some time.

Earlier in the game.

Click Here To Show Diagram Code
[go]$$Bc Sanrensei, slight error
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . a . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . 5 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Elf's winrate estimate for :b5: is 7½% less than that for a, making :b5: a likely minor error.

Click Here To Show Diagram Code
[go]$$Wcm6 Takemiya kosumi, minor errors
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . 3 . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . 5 . . . . . . . . . . . 4 . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . 2 . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . 1 . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


In 1976 I played the kosumi response in a 5 stone game vs. a pro in Kyoto. I don't know when Takemiya had the idea. In any event, Elf thinks that :b7: loses 8% to par, and :b9: loses 9½%. It believes that each should approach the top left corner. :w10: encloses the corner. I don't usually report minor errors, but I thought that these were of some interest. By :w10: Elf reckons that Takemiya has lost a net 20% to par.

Click Here To Show Diagram Code
[go]$$Bcm11 Black tenuki, significant error
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . O . 3 2 . . |
$$ | . . . , . . . . . 1 . . . . . X 4 . . |
$$ | . . O . . . . . . . . . . . X . . 8 . |
$$ | . . . . . . . . . . . . . . . . 5 6 . |
$$ | . . . . . . . . . . . . . . . . a 7 . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . O . . . . . 9 . . . . . X . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


I was never confident of handling the cut at a, and so avoided the kosumi or blocked at 14. Elf thinks that :b19: loses 16½% to the solid connection at a. Considering Black's low winrate estimate after :w18: of 33%, we might consider :b19: to be a blunder.

Click Here To Show Diagram Code
[go]$$Bcm19 Elf's mainline variation for :b19:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . 3 2 4 . . |
$$ | . . . O . . . . . . . . . O a X O . . |
$$ | . . . , . . . . . X . . . . . X O . . |
$$ | . . O . . . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . . . . . . . . . . . . . . 1 X . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . 9 . . . . X . . . . |
$$ | . . . O . . . . . , . . . . . X . . . |
$$ | . . . . . 8 . . 7 . 6 . . O . . . . . |
$$ | . . . . . . . . . . . . . . 5 . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


After :b19: White lives in the corner with the hane-and-connect. OC, the cut at a is smaller than the cut at 19. The territorial footsweep, :b23:, is interesting. It does not seem to be in line with the general aim of the sanrensei. After :w24: extends, not really making a base because of :b23:, :b25: and :b27: attack the bottom side White group.

Game continuation.

Click Here To Show Diagram Code
[go]$$Wcm20 :b29: a blunder?
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . O . X O . . |
$$ | . . . , . . . . . X . . . . . X O . . |
$$ | . . O . 0 . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . . . . . . . . . . . . . 2 1 X . |
$$ | . . . . . . . . . . . . . . . 4 3 . . |
$$ | . . . . . . . . . . . . . . . 6 5 . . |
$$ | . . . , . . . . . , . . . . . X 7 . . |
$$ | . . . . . . . . . . . . . . . . 8 9 . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . O . . . . . X . . . . . X . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Elf thinks that :b29:, a standard reducing play, loses 16% to par. We should probably consider it a blunder, because White now has a winrate estimate of 95½%.

Click Here To Show Diagram Code
[go]$$Bcm29 Elf's mainline variation for :b29:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . O . X O . . |
$$ | . . . , . . . . . X . . . . . X O . . |
$$ | . . O . . . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . . . . . . . . . . . . . X O X . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X O 2 . |
$$ | . . . , . . . . . , . . . . . X O 1 4 |
$$ | . . . . . . . . . . . . . . . 9 X O . |
$$ | . . . . . . . . . . . . . . . . 8 3 . |
$$ | . . . . . . . . . . . . . . . . 0 . . |
$$ | . . 6 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . O . . . . . X . . . . . X . . . |
$$ | . . . . . 5 . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . 7 . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Black plays kikashi against the White group on the right side, then makes a territorial moyo on the bottom. :w36: and :w38: intrude into the bottom right. Note that Black's kikashi means that the :b31: stone has some aji there.

Click Here To Show Diagram Code
[go]$$Bcm39 Elf's mainline variation for :b29:, continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O 1 . . 3 . . . . . O . X O . . |
$$ | . . . 2 . . . . . X . . . . . X O . . |
$$ | . . O . . . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . . . . . . . . . . . . . X O X . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X O O . |
$$ | . . . , . . . . . , . . . . . X O . O |
$$ | . . . . . . . . . . . . . . . X X O . |
$$ | . . . . . . . . . . . . . . . . O X . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . O . . . . . X . . . . . X . . . |
$$ | . . . . . X . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Next, Black develops the top side, staring with the third line attachment, :b39:.

I could have stopped here. However, I do not like to end on a play that Elf considers a mistake, because it typically has very few playouts, and its winrate may not be very reliable. In addition, a series of errors follows, which may be of some interest. :)

Click Here To Show Diagram Code
[go]$$Wcm30 Dueling blunders
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . O . X O . . |
$$ | . . . , . . . . . X . . . . . X O . . |
$$ | . . O . X . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . 1 . . . . . . . . . . . X O X . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . , . . . . . , . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . O . . . . . X . . . . . X . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:w30: looks funny, and indeed, Elf thinks that it loses 16½% to par. It is not unusual to see players trading mistakes of approximately the same size (from Elf's perspective). Perhaps from a mutual blindspot, from shared assumptions or evauations, or from mutual unfamiliarity with such a position. Although in this case Takemiya should be on more familiar territory.

Click Here To Show Diagram Code
[go]$$Wcm30 Elf's mainline variation for :w30:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . 5 8 . . . . . . . . . . . . . |
$$ | . . . O 4 6 . . . . . . . O . X O . . |
$$ | . . . 7 . . . . . X . . . . . X O . . |
$$ | . . O . X . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . . . . . . . . . . . . . X O X . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . , . . . . . , . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . 2 X O . |
$$ | . . . . . . . . . . . . . . . . 1 . . |
$$ | . . . . . . . . . . . . . . . . . 3 . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . O . . . . . X . . . . . X . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


As we have seen before, White expands his territory on the right side. Then :b33: plays the jump attachment on the third line against White's enclosure. In this position :b35: pulls back to secure territory on the top side and then :w36: secures the corner.

Click Here To Show Diagram Code
[go]$$Wcm30 Dueling blunders, continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . O . X O . . |
$$ | . . . , . . . . . X . . . . . X O . . |
$$ | . . O . X . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . O . . . . . . . . . . . X O X . |
$$ | . . . . . 2 . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . , . . . . . , . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . O . . . . . X . . . . . X . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:b31: looks funny, or impressive, depending on your viewpoint. Elf is not impressed. It thinks that :b31: loses 15% to par.

Click Here To Show Diagram Code
[go]$$Bcm31 Elf's mainline variation for :b31:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . 6 . . . . . . . . . . . . . . |
$$ | . . 0 O 5 8 . . . . . . . O . X O . . |
$$ | . . . 7 9 . . . . X . . . . . X O . . |
$$ | . . O . X . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . O . . . . . . . . . . . X O X . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X O 2 . |
$$ | . . . , . . . . . , . . . . . X O 1 4 |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . . . . . . . . . . . . . . . 3 . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . O . . . . . X . . . . . X . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Black takes his kikashi against the right side group and then takes aim at the top left corner, in sequences we have seen before.

Click Here To Show Diagram Code
[go]$$Bcm41 Elf's mainline variation for :b31:, continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . 4 . . O . 2 . . . . . . . . . . . . |
$$ | 6 3 O O X O . . . . . . . O . X O . . |
$$ | . . 1 X X . . . . X . . . . . X O . . |
$$ | . 5 O . X . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . O . . . . . . . . . . . X O X . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X O O . |
$$ | . . . , . . . . . , . . . . . X O . O |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . . . . . . . . . . . . . . . X . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . O . . . . . X . . . . . X . . . |
$$ | . . . . . 7 . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


In this position :b47: does not connect, but approaches the bottom left corner from the bottom side.

Back to the game

Click Here To Show Diagram Code
[go]$$Wcm32 Not so bad
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . O . X O . . |
$$ | . . . , . . . . . X . . . . . X O . . |
$$ | . . O . X . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . O . . . . . . . . . . . X O X . |
$$ | . . . . . X . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . , . . . . . , . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . O . . 1 . . X . . . . . X . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:w32: is not so bad, losing only 9½% to par, according to Elf.

Click Here To Show Diagram Code
[go]$$Wcm32 Elf's mainline variation for :w32:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . 5 . . . . . . . . . . . . . . |
$$ | . . 9 O 4 7 . . . . . . . O . X O . . |
$$ | . . 0 6 8 . . . . X . . . . . X O . . |
$$ | . . O . X . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . O . . . . . . . . . . . X O X . |
$$ | . . . . . X . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . , . . . . . , . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . 2 X O . |
$$ | . . . . . . . . . . . . . . . . 1 . . |
$$ | . . . . . . . . . . . . . . . . . 3 . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . O . . . . . X . . . . . X . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


By now this sequence is no surprise. :)

Click Here To Show Diagram Code
[go]$$Wcm42 Elf's mainline variation for :w32:, continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . 3 . . O . 1 . . . . . . . . . . . . |
$$ | 5 2 O O X O . . . . . . . O . X O . . |
$$ | . . X X X . . . . X . . . . . X O . . |
$$ | . 4 O . X . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . O . . . . . . . . . . . X O X . |
$$ | . . . . . X . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . , . . . . . , . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X X O . |
$$ | . . . . . . . . . . . . . . . . O . . |
$$ | . . . . . . . . . . . . . . . . . O . |
$$ | . . 6 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . O . . . . . X . . . . . X . . . |
$$ | . . . . . 7 . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


In this position Black prefers to approach the bottom left corner from the left side.

One more time.

Click Here To Show Diagram Code
[go]$$Wcm30 Black returns the favor, once more
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . O . X O . . |
$$ | . . . , . . . . . X . . . . . X O . . |
$$ | . . O . X . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . O . . . . . . . . . . . X O X . |
$$ | . . . . . X . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . , . . . . . , . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . 4 . . . . . . X . . . . |
$$ | . . . O . . O 5 . X . . . . . X . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:b33: returns the favor, losing 10½% to par, according to Elf. Then :w34: is only a minor mistake. I guess these mistakes are caused by a shared evaluation of this and other areas of the board.

Click Here To Show Diagram Code
[go]$$Bcm33 Elf's mainline variation for :b33:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . 6 . . . . . . . . . . . . . . |
$$ | . . 0 O 5 8 . . . . . . . O . X O . . |
$$ | . . . 9 7 . . . . X . . . . . X O . . |
$$ | . . O . X . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . O . . . . . . . . . . . X O X . |
$$ | . . . . . X . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X O 2 . |
$$ | . . . , . . . . . , . . . . . X O 1 4 |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . . . . . . . . . . . . . . . 3 . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . O . . O . . X . . . . . X . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Familiar territory.

Click Here To Show Diagram Code
[go]$$Bcm43 Elf's mainline variation for :b33:, continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . 4 . . O . 2 . . . . . . . . . . . . |
$$ | 6 3 O O X O . . . . . . . O . X O . . |
$$ | . . 1 X X . . . . X . . . . . X O . . |
$$ | . 5 O . X . . . . . . . . . X . . O . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . O . . . . . . . . . . . X O X . |
$$ | . . . . . X . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X O O . |
$$ | . . . , . . . . . , . . . . . X O . O |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . . . . . . . . . . . . . . . X . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . X . . . . |
$$ | . . . O . . O . . X . . . . . X . . . |
$$ | . . . . . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


By this time, other pros had learned how to play against Cosmic Go. Well, sort of. They still made a lot of mistakes. BTW, Takemiya won by 3½ pts. ;)

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins
----
Many are cold, but few are frozen.


Last edited by Bill Spight on Wed Nov 13, 2019 11:26 am, edited 2 times in total.

This post by Bill Spight was liked by: Gomoto
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 Post subject: Re: How is your positional judgement?
Post #134 Posted: Fri Oct 25, 2019 2:29 am 
Gosei

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Let's burn all go books. :twisted: Never mind and don't ask. (I prefer Fahrenheit over Celsius only when considering books.)

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 Post subject: Re: How is your positional judgement?
Post #135 Posted: Mon Oct 28, 2019 5:08 pm 
Honinbo

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My discussion of Elf's commentary on Game 15

Kim Tongyeop, 9 dan (W) - Kim Ilhwan, 9 dan, 2018-08-07a

After :b29: Elf estimates a Black winrate of 94½% with 23k playouts. Black, Kim Ilhwan, won by 3½ pts.

Click Here To Show Diagram Code
[go]$$Bcm29 Black is ahead
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . . . . . . |
$$ | . . O , O X . . . , . . . . . , . . . |
$$ | . . . X X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | . O . X . . . . . . . . . . . . . . . |
$$ | . O . X O O . O . . . . . . . . . . . |
$$ | . . O O X . . . O , . . . . . X . . . |
$$ | . O . . X . X . . . . . . . . . . . . |
$$ | . O X X . . . . X . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


In the bottom left corner White has made life and also has a weakish group in the center, a not uncommon joseki pattern. It seems that White's corner life is too small, or its center group is too weak, or both.

Click Here To Show Diagram Code
[go]$$Wcm30 Elf's mainline continuation after :b29:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . . . . . . |
$$ | . . O , O X 7 . . , . . . . . , . . . |
$$ | . . . X X 1 3 6 . . . . . . . . . . . |
$$ | . . . . . 2 4 5 9 . . . . . . . . . . |
$$ | . X X . . . . 8 0 . . . . . . . . . . |
$$ | . O . X . . . . . . . . . . . . . . . |
$$ | . O . X O O . O . . . . . . . . . . . |
$$ | . . O O X . . . O , . . . . . X . . . |
$$ | . O . . X . X . . . . . . . . . . . . |
$$ | . O X X . . . . X . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:w30: cuts in the center, and then White pushes Black towards White's floating stones. It looks like White's plan is sacrifice some or all of his weak stones.

Click Here To Show Diagram Code
[go]$$Wcm40 Elf's mainline after :b29:, continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . O . . . . . . . . . . . . . . |
$$ | . . O , O X O a . , . . . . . , . . . |
$$ | . . . X X O O X . . . . . . . . . . . |
$$ | . . . . 2 X X O O . . . . . . . . . . |
$$ | . X X . b 1 3 X X . . . . . . . . . . |
$$ | . O . X . . . . . . . . . . . . . . . |
$$ | . O . X O O . O . . . . . . . . . . . |
$$ | . . O O X . . . O , . . . . . X . . . |
$$ | . O . . X . X . . . . . . . . . . . . |
$$ | . O X X . . . . X . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:w40: is a nice tesuji. :w42: makes a table shape. OC, now Black a can capture some White stones. If :b41: connects at 42, White makes a bamboo joint at b. So it appears that White is not going to sacrifice any of his original floating stones.

Earlier in the game.

Click Here To Show Diagram Code
[go]$$Wcm6 Joseki, but . . . .
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 6 . . . . . . . . . . . . . . . |
$$ | . . . 2 5 7 . . . . . . . . . . . . . |
$$ | . . O 3 4 . . . 1 , . . . . . X . . . |
$$ | . . . . X . . . . . . . . . . . . . . |
$$ | . . 8 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:w6: - :b13: is joseki. but Elf reckons that White loses 16%; :w6: loses 8% and :w8: also loses 8%.

Click Here To Show Diagram Code
[go]$$Wcm6 Kosumi for :w6:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . 5 . . . . . . . . . . . . . |
$$ | . . 3 , . . . . . , . . . . . X . . . |
$$ | . . 2 4 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . 6 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 1 . . . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . X . . . |
$$ | . . . . X . . . . . . . . . . . 7 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Bots do not like premature pincers. Elf prefers the kosumi respones for :w6:. Then Black approaches the top left corner and White plays the kick and extend joseki. Not long ago :b11: might have been criticized for being neither here not there, too far away from the White stones in the bottom left for an effective pincer, and also too far from the Black stones in the top left for an extension. OC, the old rules no longer apply. White does not reply, but invades the bottom right corner.

Click Here To Show Diagram Code
[go]$$Wcm8 Elf's mainline for :w8:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O 7 . . . . . . . . . . . . . . |
$$ | . . 5 , 6 8 . . . , . . . . . X . . . |
$$ | . 9 4 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 3 . . . . . . . . . . . . . . . . |
$$ | . . . 2 . . . . . . . . . . . . . . . |
$$ | . . 1 X . . . . . . . . . . . . . . . |
$$ | . . O , . . . . W , . . . . . X . . . |
$$ | . . . . X . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


With the three space high pincer, :wc:, the push and cut is not very severe. Elf prefers to reply on the third line. Against :b11: White plays the kick, but Black plays the keima, :b13:, instead of the stand. Again, Elf prefers to reply on the third line. :b15: extends on the fourth line, and :w15: plays the underneath hane on the left side.

Click Here To Show Diagram Code
[go]$$Bcm17 Elf's mainline for :w8:, continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O O 1 . . . . . . . . . . . . . |
$$ | . . O , X X . . . , . . . . . X . . . |
$$ | . O X 3 . . . . . . . . . . . . . . . |
$$ | . . 2 . . . . . . . . . . . . . . . . |
$$ | . 4 . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . O X . . . . . . . . . . . . . . . |
$$ | . . O , . . . . W , . . . . . X . . . |
$$ | . . . . X . . . . . 5 . . . . . 6 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:b17: plays the turn on the top side, a big play. Then :w18: attaries on the left side. The result in the top left is as though White started with a play at C-16 and Black played the high approach. :b21: plays a one space low pincer against :wc: and then :w22: jumps into the bottom right corner.

Back to the game.

Click Here To Show Diagram Code
[go]$$Wcm14 White gets enclosed for small life
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . 8 4 . . . . . . . . . . . . . . . . |
$$ | . 3 . X . . . . . . . . . . . . . . . |
$$ | . 9 . X O O . 7 . . . . . . . . . . . |
$$ | . . O O X . . . W , . . . . . X . . . |
$$ | . 5 . . X . 6 . . . . . . . . . . . . |
$$ | . 1 X 2 . . . . 0 . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:w14: plays the attachment on the 2-2 and Black pulls back. Next :w16: plays the keima and :b17: replies. :w18: is a dual purpose play, saving :w14: and making some eye space, but Elf says that it loses 13%. :b19: is a one space extension, making eye space and threatening to separate the central White stones. Elf thinks it is a minor error, losing 6%. :w20: connects White's stones and threatens Black's group. Elf thinks that it loses 15½%. Before sliding out into the bottom side Black blocks at :b21: with sente, enclosing the White group and forcing it to make small life.

By now the main damage has been done. Elf estimates Black's winrate as 88% with 71.8k playouts. White's sins have added up. First, White played a premature three space high pincer and then followed with the push and cut. Then, White allowed Black to enclose the Wbite group into the corner and force it to make small life.

Click Here To Show Diagram Code
[go]$$Wcm18 Elf's main variation for :w18:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . 2 . . 6 . . . . . . . . . . . . . |
$$ | . 5 3 4 . . . . . . . . . . . . . . . |
$$ | . 1 X . . . . . . . . . . . . . . . . |
$$ | . O . X . . . . . . . . . . . . . . . |
$$ | . . . X O O . . . . . . . . . . . . . |
$$ | . 9 O O X . 7 . O , . . . . . X . . . |
$$ | . 8 . . X . . . . . . . . . . . . . . |
$$ | . W X X . . . . . . . . . . . . . . . |
$$ | . 0 . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:w18: simply crawls along the second line so as not to keep from getting easily enclosed. After :b19: jumps :w20: plays a wedge. :b23: makes a keima connection, then :w24: connects his outside stones and puts pressure on Black's stones in the corner. Black thens captures the :wc: stone and makes life.

Click Here To Show Diagram Code
[go]$$Wcm28 Elf's main variation for :w18:, continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . 4 . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 1 , . . . . . , . . . . . , . . . |
$$ | . 3 X 2 . X . . . . . . . . . . . . . |
$$ | . O O X . . . . . . . . . . . . . . . |
$$ | . O X . . . . . . . . . . . . . . . . |
$$ | . O . X . . . . . . . . . . . . . . . |
$$ | . . . X O O . . . . . . . . . . . . . |
$$ | . O O O X . O . O , . . . . . X . . . |
$$ | . X . . X . . . . . . . . . . . . . . |
$$ | . O X X . . . . . . . . . . . . . . . |
$$ | . X . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:w28: plays the clamp and escapes to the left side. Then Black plays the AI 4-4 attachment in the top left corner. White has avoided getting enclosed in the bottom left corner and his bottom side stones are healthier than in the game. OC, because of his previous errors Elf still says that Black is ahead.

Click Here To Show Diagram Code
[go]$$Wcm20 Elf's main variation for :w20:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . . . . . . . . . . . |
$$ | . . . 8 . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . 7 . . . . . . . . . . . . . . . . |
$$ | . . 5 6 . . . . . . . . . . . . . . . |
$$ | . 1 X . . 2 . . . . . . . . . . . . . |
$$ | . O . X . . . . . . . . . . . . . . . |
$$ | . . . X O O . 3 . . . . . . . . . . . |
$$ | . . O O X . . . O , . . . . . X . . . |
$$ | . W . . X . X . . . . . . . . . . . . |
$$ | . O X X . . . . 4 . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


As above, :w20: keeps from being easily enclosed. :b21: threatens White's outside stones, :w22: connects and then :b23: lives and undercuts the White stones. White then pushes out into the left side and Black plays the attachment in the top left corner. Because of White's error, :wc:, the White stones on the bottom are not as healthy as above.

Up to :b27: White made only a small error after :w20:. White's errors, :w18: and :w20: illustrate the importance of the basics. Avoid getting enclosed in a corner, and avoid having to make small life.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins
----
Many are cold, but few are frozen.


Last edited by Bill Spight on Tue Dec 03, 2019 11:16 am, edited 2 times in total.
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 Post subject: Re: How is your positional judgement?
Post #136 Posted: Sat Nov 09, 2019 8:08 am 
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My discussion of Elf's commentary on Game 16

O Rissei, 9dan (W) - Kato Masao, 9 dan, 1998-02-19a

After :b27: Elf estimates White's winrate as 89% with 59.6k playouts. White, O Rissei, won by 1½ pts.

Click Here To Show Diagram Code
[go]$$Bcm23 White is ahead
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . O . . . . . . |
$$ | . . . . . . . . . 2 a X O . . . . . . |
$$ | . . . O . . . . 4 1 O O X O O , O O . |
$$ | . . . . . . . . . 5 3 . X X . . X . . |
$$ | . . . . . . . . . . X . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Black's bad shape, the empty triangle on the bottom side, is a clue. However, Kato, who was no slouch, had just played to create it. Perhaps he thought that :w28: would connect at a. If so, he was right, O Rissei did play :w28: at a. Elf disagrees. It regards :w28: as a blunder, costing 19%.

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


:w28: is big, enlarging White's right side moyo. Instead of replying to :b29: White turns to the top side, making a three stone wall. Next, the cut at :b33: is big. :w34: is interesting, avoiding an extension towards the right, which would not have a good follow-up to its right. :w36: approaches the top right enclosure. It may also be considered as an extension from the three stone White wall. OC, the bots do not care about the human rules for such extensions. ;)

Earlier in the game

Click Here To Show Diagram Code
[go]$$Wcm14 :w14: loses 13% versus a
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . , 1 . a O O , O . . |
$$ | . . . . . . . . . . . . X X . . . . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Elf regards :w14: as a mistake, preferring the simple and strong push at a.

Click Here To Show Diagram Code
[go]$$Wcm14 Elf's mainline variation for :w14:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X 3 . . . . . . . X . . . . . |
$$ | . . X , 4 O . . . , . . . . . , X . . |
$$ | . . . . . 5 . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 0 . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 6 8 . . . . . . . . . . . . . . . |
$$ | . . 7 . . . . . . . . . . . . . . . . |
$$ | . . . O . 9 . . . , . . 1 O O , O . . |
$$ | . . . . . . . . . . . 2 X X . . . . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


After :b15: White turns to the top left corner, making the three stone wall. White replies to :b19: with a kick and jump. The fact that :w22: is high suggests that White is looking to attack :b19: and :b21:.

Click Here To Show Diagram Code
[go]$$Wcm24 Elf's mainline variation for :w14:, continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X O . . . . . . 2 X . . . . . |
$$ | . . X , X O . . . , 3 . 1 . . , X . . |
$$ | . . . . . O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 5 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . B B . . . . . . . . . . . . . . . |
$$ | . 7 O . . . . . . . . . . . . . . . . |
$$ | . . . O . O . . . , . . O O O , O . . |
$$ | . . 6 . . . . . . . . X X X . . . . . |
$$ | . . . . 4 . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:w24: plays the Go Seigen/AI shoulder blow against the top right enclosure. :b27: takes advantage of White's high posture in the bottom left corner to play a submarine attack. :w28: and :w30: play a counterattack against the :bc: stones.

The actual game continues.

Click Here To Show Diagram Code
[go]$$Wcm20 Mutual misunderstanding
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . X O . . . . . . |
$$ | . . . O . . . . . , O 1 X O O , O O . |
$$ | . . . . . . . . . . . . X X . . X . . |
$$ | . . . . . . . . . . 2 . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


Elf estimates that :w20: loses 15½% to par. :b21: returns the favor, losing 17½%. This kind of exchange of nearly equal mistakes suggests a shared misunderstanding of the position.

Click Here To Show Diagram Code
[go]$$Wcm20 Elf's mainline variation for :w20:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . 1 . . . . . . |
$$ | . . . . . . . . . 4 2 B O . . . . . . |
$$ | . . . O . . . . 3 5 W 6 X O O , O O . |
$$ | . . . . . 7 . . . . . . X X . . X . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:w20: stands instead of cutting off the :bc: stone. OC, cutting off the :bc: stone shows fighting spirit, and is consistent with :w14: ( :wc: ). Not to cut off the :bc: stone suggests that :w14: was a mistake. Elf would agree. ;)

:b21: and :b23: push along the fifth line, forming a center facing wall, before connecting with :b25:. :w22: jumps along the fourth line and then:w24: connects. In effect, Black has forced White to "crawl" along the fourth line. According to traditional go wisdom, that is ill advised. However, the bots ofter prefer to make center facing walls on the fifth line in exchange for the opponent's edge facing walls on the fourth line. The bots have a lot to teach us about center oriented play.

Click Here To Show Diagram Code
[go]$$Bcm27 Elf's mainline variation for :w20:, II
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . 7 X . . |
$$ | . . . . . . . . . . . . . . 2 . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 1 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . 4 . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . 5 . 3 . . . |
$$ | . . . . . . . . . . . . . . . . 6 . . |
$$ | . . . . . . . . . . . . O . . . . . . |
$$ | . . . . . . . . . X X X O . . . . . . |
$$ | . . . O . . . . O O O X X O O , O O . |
$$ | . . . . . O . . . . . . X X . . X . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:b27: approaches White's small moyo on the right side. The resulting sequence illustrates Elf's light, flexible play. :w28: on the 5-5 threatens to cut off :b27: or to invade the Black enclosure. :b29: invades the White moyo. OC, Black's fifth line wall offers support for this invasion. :w30: separates :b27: and :b29:, attacking both. :b31: jumps out into the center and then :w32: defends the White territory. Finally, :b33: defends the Black position in the top right.

Click Here To Show Diagram Code
[go]$$Wcm34 Elf's mainline variation for :w20:, III
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X 1 . . . . . . . X . . . . . |
$$ | . . X , 2 O . . . 4 . . . . . X X . . |
$$ | . . . . 8 3 . . . . . . . . O . . . . |
$$ | . . . 7 9 0 . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . 5 X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . O . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . X . X . . . |
$$ | . . . . . . . . . . . 6 . . . . O . . |
$$ | . . . . . . . . . . . . O . . . . . . |
$$ | . . . . . . . . . X X X O . . . . . . |
$$ | . . . O . . . . O O O X X O O , O O . |
$$ | . . . . . O . . . . . . X X . . X . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:w34: builds the three stones wall on the top side. Then :b37: attacks it while extending on the side. :w38: bolsters White's position in the top right and then :b39: defends his invasion. :w40: takes the double keima, then :b41: and :b43: push and cut, and the opening fight continues.

Next we look at Elf's variation for :b21: in the actual game

Click Here To Show Diagram Code
[go]$$Bcm21 Elf's mainline variation for :b21:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . 6 5 7 . . . . . |
$$ | . . . . . . . . . 9 . 1 2 . 8 . . . . |
$$ | . . . . . . . . . 3 . X O . . . . . . |
$$ | . . . O . . . . . 4 W W X O O , O O . |
$$ | . . . . . . . . . . . . X X . . X . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


The stand, :b21:, looks right and left, taking aim at the :wc: stones and at White's weakness in the bottom right. :b23: threatens the one and then :b25: threatens the other. :w26: is a strong riposte, cutting Black in two.

Click Here To Show Diagram Code
[go]$$Wcm30 Elf's mainline variation for :b21:, continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . O X X . . . . . |
$$ | . . . . . . . . . X . X O . O . . . . |
$$ | . . . . . . . . . X . X O . . . . . . |
$$ | . . . O . . . . . O O O X O O 3 O O . |
$$ | . . . . . . . . . . . 5 X X 6 . X 2 . |
$$ | . . . . . . . . . . . 1 4 . a X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:w30: turns to attacking the Black corner. :w32: shores up a White weakness and threatens to play at a. :b33: and :b35: secure the Black group.

Back to the game.

Click Here To Show Diagram Code
[go]$$Wcm22 Overplay
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . 1 . . . . . . |
$$ | . . . . . . . . . . . X O . . . . . . |
$$ | . . . O . . . . . 2 O O X O O , O O . |
$$ | . . . . . . . . . . . . X X . . X . . |
$$ | . . . . . . . . . . X . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:b23: may be a tesuji. but Elf indicates that it is an overplay, losing 13½% to par.

Click Here To Show Diagram Code
[go]$$Bcm23 Elf's mainline variation for :b23:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X 6 . . . . . 0 . X . . . . . |
$$ | . . X , 7 O . . . , . . . . . , X . . |
$$ | . . . . . 8 . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . .9. . . . . . . . . . . . 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . 5 . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 3 . . . . . . . . . O . . . . . . |
$$ | . 4 . . . . . . . . . B O . . . . . . |
$$ | . . . O . . . . . . O O X O O , O O . |
$$ | . . . . . . . . . 1 . . X X . . X . . |
$$ | . . . . . . . . . . X . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:b23: is a solid play, but gote. The checking extension, :w24:, is big. :b25: approaches the bottom left corner. White replies with the footsweep, :w26:, as :b23: hinders White's development on the bottom side. :b27: is an interesting play, threatening to save :bc:, as well as to invade the right side. White now turns to develop the top side, as we have seen above.

Back to the game.

Click Here To Show Diagram Code
[go]$$Wcm24 Blunder
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . . . . . . . . X . . . . . |
$$ | . . X , . O . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . O . . . . . . |
$$ | . . . . . . . . . 1 . X O . . . . . . |
$$ | . . . O . . . . 3 X W W X O O , O O . |
$$ | . . . . . . . . . 4 2 . X X . . X . . |
$$ | . . . . . . . . . . X . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]


:b25: threatens the :wc: stones, but it is a blunder. According to Elf it loses 30%. :shock:

Click Here To Show Diagram Code
[go]$$Bcm25 Elf's mainline variation for :b25:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X 8 . . . . . . . X . . . . . |
$$ | . . X , 9 O . . . , . . . . . , X . . |
$$ | . . . . . 0 . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 2 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . O . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . 3 . B . . . . . . . O . . . . . . |
$$ | . . . . . . . . 4 O . X O . . . . . . |
$$ | . 5 . O . . . 6 1 X O O X O O , O O . |
$$ | . . . . . . . . . a . . X X . . X . . |
$$ | . . . . . . . . 7 . X . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

:bc: = :b35:

:b25: is typical when Black does not need to play at a. In this position, White does not answer :b27: in the corner, but pushes in the center. After the now rare slide, :b29:, White plays the hane, :w30:, and :b31: protects, forming a table shape. Next, White forms a three stones wall on the top side. Then :b35: jumps into the center.

Attack and Kill Kato blundered on the bottom side with a strong local attack, accepting bad shape in the process. He probably assumed that O Rissei would save his two stones, which he did, making his own blunder. We warn beginners against overvaluing a few stones. It just goes to show that even 9 dans can sometimes make kyu level plays.

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins
----
Many are cold, but few are frozen.


Last edited by Bill Spight on Wed Nov 13, 2019 11:30 am, edited 1 time in total.
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 Post subject: Re: How is your positional judgement?
Post #137 Posted: Sat Nov 09, 2019 3:30 pm 
Lives in gote

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Uberdude wrote:
Elfv2 (which I think is what was used for the historical analysis Bill is using, but not sure) is way more extreme than that, a pass for the first move gives white >98.5%.

Surely a pass on the first move means that white can also pass and win by komi? So actually the winrate should be 100%, but 98.5% is within the margin of error :-) Do you get the same result if you make an SGF file that has an empty board and "white to play" (so there isn't a previous black pass)?

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 Post subject: Re: How is your positional judgement?
Post #138 Posted: Mon Nov 25, 2019 4:55 am 
Gosei
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I've started https://senseis.xmp.net/?BillSpightsElf ... tExercises

If someone wants to help out doing the C&P work, be my fellow!


This post by Knotwilg was liked by: Bill Spight
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 Post subject: Re: How is your positional judgement?
Post #139 Posted: Sun Dec 01, 2019 5:50 pm 
Honinbo

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I posted Game 25 today. :)

During the holiday season I plan to catch up with the comments. I may post another game, but maybe not.

Enjoy your holidays. :D

Or, as we say in the US, Happy War on Christmas! :mrgreen:

_________________
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins
----
Many are cold, but few are frozen.

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