How is your positional judgement? Game 28

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Bill Spight
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How is your positional judgement? Game 28

Post by Bill Spight »

The Elf commentary, assuming area scoring and a 7½ pt. komi, gives one player after :w30: a winrate estimate of 91% with 39k rollouts. Which player is it?
Click Here To Show Diagram Code
[go]$$Wcm30 Black to play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . O . . . . O . . . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X O . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . X . O O . . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . X , . . . . . , O . . X X X X O . |
$$ | . . . . . X . O . . . . . . . X . X O |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Black has captured 2 White stones.

Enjoy! :)
Last edited by Bill Spight on Fri Jan 03, 2020 11:51 am, edited 1 time in total.
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— Winona Adkins

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Knotwilg
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Re: How is your positional judgement? Game 28

Post by Knotwilg »

Another difficult position
At first sight, White has successfully disrupted Black's framework and established a live group on both sides. Black's stones in the lower right look like a lump and inefficient. White's framework on the upper left is free for development.

On the other hand, White's lower right is not out of trouble yet:
Click Here To Show Diagram Code
[go]$$B Black to play
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O . . . . . O . . . . O . . . . |
$$ | . . . , . . . . . , . . . . . , X . . |
$$ | . . . . . . . . . . . . . . . X . . . |
$$ | . . O . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , O 7 . |
$$ | . . . . . . . . . . . . . . . 6 5 3 . |
$$ | . . . . . . . . . . . . . . . 4 X O 9 |
$$ | . . . . . . . . . . . . . . a . 2 1 . |
$$ | . . . . . . . . . . . . . X . O O 8 . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . X , . . . . . , O . . X X X X O . |
$$ | . . . . . X . O . . . . . . . X . X O |
$$ | . . . . . . . . . . . . . . . . X . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
If White doesn't spend another move, a Black peep at A turns the group into a liability again. Black has territory in three places

Visually I say: White leads
After seeing the variation I say: Black leads.
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jlt
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Re: How is your positional judgement? Game 28

Post by jlt »

Black has 15 stones on the board and White has 13, so I suppose that Black has captured 2 stones (at Q4 and R3) ?
Not obvious. At first sight, Black's shape in the lower right looks ugly. On the other hand, bots probably don't like 5-space extensions like K17. In addition, Black has no weaknesses. The upper left corner is equivalent to the lower left corner, but the lower right corner is entiretly Black's, and Black has a better control than White on the upper right corner. White's position is lower than Black's. So on second thought I prefer Black.
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Re: How is your positional judgement? Game 28

Post by Bill Spight »

jlt wrote:Black has 15 stones on the board and White has 13, so I suppose that Black has captured 2 stones (at Q4 and R3) ?
Thanks. Typo corrected. :)
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Re: How is your positional judgement? Game 28

Post by xela »

Black.

Initial impression was that black's shape at bottom right is inefficient, while white's top left looks much healthier. And white's stones on the right are slightly fragile, but I can't see a strong way for black to attack them. So initially I preferred white.

But on reflection: white's stones at the bottom are also not settled yet. Two unsettled white groups, with thick black stones in between them ... looks like there's some trouble ahead? And I'm thinking of John's comments in the other thread, along the lines of "you call that thick? but it's not doing any of the work that a thick group should do!". In this case black has a couple of clear targets to attack, and the lower right group could end up doing some serious work!
Great to see this series revived! Holding my breath now for the "answers" to games 24-27 :-)
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Re: How is your positional judgement? Game 28

Post by dhu163 »

B has one more stone in the lower right but has captured it all, damaging L4 also. Next, Q8 can keep up an attack, but it doesn't seem to work yet. S9, S7 seem to work even worse though as W naturally gets S5. Later any move around N8 will be threatening. W will need to work to live with 3 weak groups even if none can be attacked for profit yet. Because W's moves to live make too little territory themselves when B is so thick. Perhaps E3 is interesting.

So switching to M17 looks natural, trying for a double attack.

Or the left side somewhere like C10.
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