Opening problems for AI: Problem 43

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Bill Spight
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Opening problems for AI: Problem 43

Post by Bill Spight »

Only move problem.

White to play.
Click Here To Show Diagram Code
[go]$$Wcm18 Where is White's only move?
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . . . . . . . . . . . . . . . |
$$ | . X X , . . . . . , . . . . . , . . . |
$$ | . . O . O . X . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Enjoy! :)
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Uberdude
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Re: Opening problems for AI: Problem 43

Post by Uberdude »

Given the hint it's the only move it's got to be d4, and if with 2 empty corners it'd be only move to me too as taking the reverse sente means you can still get last empty corner tedomari, but with 3 empty corners d4 allows black to get the last one. I suppose the drop in value from an empty corner to an approach / 3-3 invasion is not as big as the loss white suffers in sente of letting black push to ruin the shape.
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Re: Opening problems for AI: Problem 43

Post by Knotwilg »

Two possibilities:
Click Here To Show Diagram Code
[go]$$Wc
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . . . . . . . . . . . . . . . |
$$ | . X X 1 . . . . . , . . . . . , . . . |
$$ | . 2 O . O . X . . . . . . . . . . . . |
$$ | . . 3 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
The question is: is :w3: necessary?
Click Here To Show Diagram Code
[go]$$Wc Where is White's only move?
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . 6 . . . . . . . . . . . . . |
$$ | . X X 1 . . . . . , . . . . . , . . . |
$$ | . 2 O 5 O . X . . . . . . . . . . . . |
$$ | . . 4 . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
If White plays :w3: elsewhere then the group becomes a floating one. If :w5: at :b6: or ko, it's not much better.
Click Here To Show Diagram Code
[go]$$Wc Where is White's only move?
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . . . . . . . . . . . . . . . |
$$ | . X X 2 3 . . . . , . . . . . , . . . |
$$ | . 1 O . O . X . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
This is more clearly gote for White.
The result is territorially better than the gote variation above.
I read that Uberdude finds White's shape ruined.
I'm not sure which is better.
Click Here To Show Diagram Code
[go]$$Bc Follow up
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | 3 O X O 1 4 . . . . . . . . . . . . . |
$$ | . X X X O . . . . , . . . . . , . . . |
$$ | . O O 2 O . X . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Right after this, there's ladder aji. White may decide to sacrifice the 4 stones. The first variation doesn't have this aji.
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Joaz Banbeck
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Re: Opening problems for AI: Problem 43

Post by Joaz Banbeck »

This seems to preserve white's eye space as well as any move.
Click Here To Show Diagram Code
[go]$$Wcm18
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . . . . . . . . . . . . . . . |
$$ | . X X , . . . . . , . . . . . , . . . |
$$ | . . O . O . X . . . . . . . . . . . . |
$$ | . . W . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
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Re: Opening problems for AI: Problem 43

Post by Kirby »

I'd just play here:
Click Here To Show Diagram Code
[go]$$Wcm18
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . W . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . . . . . . . . . . . . . . . |
$$ | . X X , . . . . . , . . . . . , . . . |
$$ | . . O . O . X . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
or maybe here:
Click Here To Show Diagram Code
[go]$$Wcm18
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . W . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . . . . . . . . . . . . . . . |
$$ | . X X , . . . . . , . . . . . , . . . |
$$ | . . O . O . X . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Given black's potential for influence on the left..
be immersed
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Harleqin
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Re: Opening problems for AI: Problem 43

Post by Harleqin »

I'd play hoshi in the top right. Taking one of an uneven number of open corners is quite high in priority, and the lower left feels stable enough to me. Top right also protects the ladder. If White took a different corner, Black taking the top right would activate the ladder, so the remaining corners would not be miai at all.
A good system naturally covers all corner cases without further effort.
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Joaz Banbeck
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Re: Opening problems for AI: Problem 43

Post by Joaz Banbeck »

I'm highly skeptical of tenukiing to a corner. With Bill's #42 still in mind, I'm seeing honte moves in my sleep.

But I don't like playing the corner either. My gut says that a five point move in gote close to black's strength can't be best.

Perhaps there is a possibility in between.
Click Here To Show Diagram Code
[go]$$Wcm18 A compromise: not corner, but not tenuki.
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . . . . . . . . . . . . . . . |
$$ | . X X , . . . W . , . . . . . , . . . |
$$ | . . O . O . X . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
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Re: Opening problems for AI: Problem 43

Post by Uberdude »

Joaz Banbeck wrote:This seems to preserve white's eye space as well as any move.
Click Here To Show Diagram Code
[go]$$Wcm18
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . . . . . . . . . . . . . . . |
$$ | . X X , . . . . . , . . . . . , . . . |
$$ | . . O . O . X . . . . . . . . . . . . |
$$ | . . W . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Not as well as this move, which I can only see advantages and no disadvantages over your move, except perhaps making the opponent lose concentration from the shock of such a bizarre move! How can you go from so right on the last problem to so wrong here?!
Click Here To Show Diagram Code
[go]$$Wcm18
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . . . . . . . . . . . . . . . |
$$ | . X X , . . . . . , . . . . . , . . . |
$$ | . W O . O . X . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
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ez4u
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Re: Opening problems for AI: Problem 43

Post by ez4u »

Bill Spight wrote:Only move problem.

White to play...
Enjoy! :)
Huh? But you said... :scratch:
Bill Spight wrote: "Tenuki is always an option!"
:D
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Re: Opening problems for AI: Problem 43

Post by Bill Spight »

ez4u wrote:
Bill Spight wrote:Only move problem.

White to play...
Enjoy! :)
Huh? But you said... :scratch:
Bill Spight wrote: "Tenuki is always an option!"
:D
:lol:
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Re: Opening problems for AI: Problem 43

Post by Gomoto »

A hideous insidious riddle it is

I thought about B3

(mild) spoiler
but choose your corner
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Re: Opening problems for AI: Problem 43

Post by Bill Spight »

The game is GoGoD 1600-00-00d, between Honinbo Sansa (W) and Rigen. Sansa's play in the top right corner got 0 rollouts, for a loss of 17½% to par, according to Elf.

Game continuation
Click Here To Show Diagram Code
[go]$$Wcm18 Mistake after mistake
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . d . . . . . . . . . . . . b . . |
$$ | . . . c . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . 1 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . 4 . . . . . . . . . . . . . |
$$ | . X X 2 3 . . . . , . . . . . a e . . |
$$ | . . O . O . X . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Rigen pushed through with :b19: and then peeped with :b21:, another mistake that loses 14½% to par. Elf prefers to play in another corner at one of a - e.
Click Here To Show Diagram Code
[go]$$Bcm21 Mainline variation for :b21:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . 4 . 3 . . |
$$ | . . 2 , . . . . . , . . . . 6 5 . . . |
$$ | . . . . . . . . . . . . . . . O 7 . . |
$$ | . . . . . . . . . . . . . . . 8 9 . . |
$$ | . . . . . . . . . . . . . . . 0 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . . . . . . . . . . . . . . . |
$$ | . X X X O . . . . , . . . . . 1 . . . |
$$ | . . O . O . X . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Elf's top choice for :b21: is on the 4-4 in the bottom right corner, with 68.8k rollouts. After :w22: occupies the last open corner Black invades the top right corner with :b23:. A standard joseki follows, where White builds a wall and Black makes territory.
Click Here To Show Diagram Code
[go]$$Bcm31 Mainline variation for :b21:, continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . a d . . . . . . O . X . . |
$$ | . . O b . . . . . , . . . . O X . . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . . . . . . . . . . . . . . . O X . . |
$$ | . . . . . . . . . . . . . . . O 1 . . |
$$ | . . . . . . . . . . . . . . . 2 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . c 3 . . . . . . . . . . . . |
$$ | . X X X O . . . . , . . . . . X . . . |
$$ | . 4 O . O . X . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Elf's choice for :b33: is the one space jump, but a - d are all playable. :w34: plays to secure the corner.

Only play: Solid wall
Click Here To Show Diagram Code
[go]$$Wcm18 Solid wall. Only play.
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . . . . . . . . . . . . . . . |
$$ | . X X 1 . . . . . , . . . . . , . . . |
$$ | . . O . O . X . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Elf's choice, the connection at :w18:, gets a whopping 143.8k rollouts. No other play gets as many as 1500 rollouts. If there is another reasonable play, Elf did not find it.
Click Here To Show Diagram Code
[go]$$Bcm19 Mainline variation
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . 1 . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . 3 . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . . . . . . . . . . . 9 7 . . |
$$ | . X X O . . . . . , . . . . 8 5 2 . . |
$$ | . . O . O . X . . . 4 . . . . 6 0 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
After :w18: the players occupy the open corners, and then :w22: plays a three space pincer on the bottom side. :b23: replies with an attachment against :w20:. :w24: hanes on the 3d line and then :b25: plays a counter-hane towards the right side. Atari, connect-connect follow.
Click Here To Show Diagram Code
[go]$$Bcm29 Mainline variation, continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . X . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . X . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . . . . . 6 . . . . . X X . . |
$$ | . X X O . . . 2 . 4 3 5 . . O X O . . |
$$ | . 1 O . O . B . . . O . . . . O O . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
:b29: pushes into the bottom left corner and then :w30: plays a shoulder hit against the long ago pincer, :bc:. Then :b31: plays a 4th line contact play to commence reducing the bottom side.

We have had an earlier problem in this series where the connection to make a solid wall was the answer. But in this case that choice got a humungous number of rollouts, with no other play worth mentioning. I couldn't resist. ;) In this problem the pincer stone was quite close, too close for comfort to a solid wall, and there were no other distractions, except the open cornerns.

Not that White hasn't lost ground in the process of sacrificing two stones on the left side, but now that we have come so far, making a strong wall looks like the best bet by far.
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.
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yoyoma
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Re: Opening problems for AI: Problem 43

Post by yoyoma »

Click Here To Show Diagram Code
[go]$$Wcm18 katago evals:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . a . . . . . , . . . . . c . . . |
$$ | . . . . . . . . . . . . . . . d . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . . . . . . . . . . . . . . . |
$$ | . X X b . . . f . , . . . . . , . . . |
$$ | . e O . O . X . . . . . . . . . . . . |
$$ | . . g . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Code: Select all

a - 4-4 upper left  : White 49.5%  -0.1pts  (Kata's choice)
b - solid connect   : White 47.1%  -0.2pts  (Elf's "only move")
c - 4-4 upper right : White 46.8%  -0.2pts
d - 5-4 upper right : White 41.5%  -0.9pts  (Game move)
e - shoulder hit    : White 43.6%  -0.7pts
f - block corner    : White 36.1%  -1.7pts
g - descend         : White  4.3% -10.2pts
Kata is not so insistent about connecting. It's a good move, but so is taking the corners. If White takes a corner, Kata also thinks Black can choose taking a corner or playing the forcing push.
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Bill Spight
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Re: Opening problems for AI: Problem 43

Post by Bill Spight »

yoyoma wrote:
Click Here To Show Diagram Code
[go]$$Wcm18 katago evals:
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . a . . . . . , . . . . . c . . . |
$$ | . . . . . . . . . . . . . . . d . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . X X . . . . . . . . . . . . . . . . |
$$ | X . X O . . . . . . . . . . . . . . . |
$$ | . X O O . . . . . . . . . . . . . . . |
$$ | . O X O . . . . . . . . . . . . . . . |
$$ | . X X b . . . f . , . . . . . , . . . |
$$ | . e O . O . X . . . . . . . . . . . . |
$$ | . . g . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Code: Select all

a - 4-4 upper left  : White 49.5%  -0.1pts  (Kata's choice)
b - solid connect   : White 47.1%  -0.2pts  (Elf's "only move")
c - 4-4 upper right : White 46.8%  -0.2pts
d - 5-4 upper right : White 41.5%  -0.9pts  (Game move)
e - shoulder hit    : White 43.6%  -0.7pts
f - block corner    : White 36.1%  -1.7pts
g - descend         : White  4.3% -10.2pts
Kata is not so insistent about connecting. It's a good move, but so is taking the corners. If White takes a corner, Kata also thinks Black can choose taking a corner or playing the forcing push.
This is great! :)

Elf apparently developed a blind spot that kept it from exploring alternatives. It is extremely rare for it to like a play so much that it gives it over 100k rollouts.

How many rollouts does KataGo give these different options?
The Adkins Principle:
At some point, doesn't thinking have to go on?
— Winona Adkins

Visualize whirled peas.

Everything with love. Stay safe.
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Uberdude
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Re: Opening problems for AI: Problem 43

Post by Uberdude »

I've seen Elf (v2 I think) have a blindspot and some % winrate change when shown the shockingly unusual move 3 of a 3-4 point instead of a 4-4. Other bots are less blinkered and more reliable for analysis IMO.
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