The game is GoGoD 1660+v, Honinbo Dosaku (W) vs. Masaki Kasue.
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[go]$$Bcm39 Anti-suji
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O X . . . . . . . . . . . . . . |
$$ | . O X O X . . . . . . . X . . X . . . |
$$ | . O X , X . . . . , . . . . . , . . . |
$$ | . . O X X . . . . . . . . . . . O . . |
$$ | . . O O X . . . . . . . . . . . . . . |
$$ | . . . . O O . . . . . . . . . . 3 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . a . . |
$$ | . . X . . . . . . . . . . O . . 2 . . |
$$ | . . . . . . . . . . . . . X O O . . . |
$$ | . . . . . . . . . . . . . . X X O . . |
$$ | . . X , . . . . . , . . . . . 1 O . . |
$$ | . . . . O . . . . O . X . . . X X O . |
$$ | . . . . . . . . . . . . . . . . . X . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Masaki played the anti-suji,
![black 39 :b39:](./images/smilies/b39.gif)
, threatening to cut. Elf reckons that this play loses 31% to par. It is one of those plays that strengthens your opponent. I did not expect it to attract any votes.
![Wink ;)](./images/smilies/icon_e_wink.gif)
Dosaku protected against the cut with
![white 40 :w40:](./images/smilies/w40.gif)
. Then Masaki played the one space pincer in the top right corner.
Elf prefers
a to
![white 40 :w40:](./images/smilies/w40.gif)
by 2%.
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[go]$$Bcm39 Variation for ![white 40 :w40:](./images/smilies/w40.gif)
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O X . . . . . . . . . . . . . . |
$$ | . O X O X . . . . . . . X . . X . . . |
$$ | . O X , X . . . . , . . . . . , . . . |
$$ | . . O X X . . . . . . . . . 4 . O . . |
$$ | . . O O X . . . . . . . . . . . . . . |
$$ | . . . . O O . . . . . . . . . . 3 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . 2 . . |
$$ | . . X . . . . . . . . . . O . . . . . |
$$ | . . . . . . . . . . . . . X O O . . . |
$$ | . . . . . . . . . . . . . . X X O . . |
$$ | . . X , . . . . . , . . . . . 1 O . . |
$$ | . . . . O . . . . O . X . . . X X O . |
$$ | . . . . . . . . . . . . . . . . . X . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
![black 41 :b41:](./images/smilies/b41.gif)
plays the pincer, as above, and
![white 42 :w42:](./images/smilies/w42.gif)
jumps out.
The "only move"
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[go]$$Bcm39 Central two step hane
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O X . . . . . . . . . . . . . . |
$$ | . O X O X . . . . . . . X . . X . . . |
$$ | . O X , X . . . . , . . . . . , . . . |
$$ | . . O X X . . . . . . . . . . . O . . |
$$ | . . O O X . . . . . . . . . . . . . . |
$$ | . . . . O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . a . . |
$$ | . . . . . . . . . . . . . . . b . . . |
$$ | . . O , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . d . . |
$$ | . . . . . . . . . . . . 4 2 . . . . . |
$$ | . . X . . . . . . . . . 1 O . . . . . |
$$ | . . . c . . . . . . . . 3 X O O . . . |
$$ | . . . . . . . . . . . . . . X X O . . |
$$ | . . X , . . . . . , . f e . . . O . . |
$$ | . . . . O . . . . O . X . . . X X O . |
$$ | . . . . . . . . . . . . . . . . . X . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
Elf greatly prefers the two step hane, with 98.4k rollouts. No other choice gets any mention in the commentary. No other play compares, as pwaldron says.
![Smile :)](./images/smilies/icon_e_smile.gif)
I chose this position not only as an only move problem, but also because it illustrates AI play in the center, where I feel that it is head and shoulders above human play.
![Smile :)](./images/smilies/icon_e_smile.gif)
Still, as Knotwilg indicates, it induces two good plays by White, the 6th line (!) extension by White and the central turn,
![white 42 :w42:](./images/smilies/w42.gif)
. Elf greatly prefers
![white 42 :w42:](./images/smilies/w42.gif)
, giving it 88.3k rollouts. Other moves,
a -
e, in order of preference, are possible, perhaps even playable, but the second choice,
a, gets only 4k rollouts. If White plays at
e, Black replies at
f.
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[go]$$Wc Kikasare
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O X . . . . . . . . . . . . . . |
$$ | . O X O X . . . . . . . X . . X . . . |
$$ | . O X , X . . . . , . . . . . , . . . |
$$ | . . O X X . . . . . . . . . . . O . . |
$$ | . . O O X . . . . . . . . . . . . . . |
$$ | . . . . O O . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . O , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . X . . . . . . . . . a O . . . . . |
$$ | . . . . . . . . . . . . 1 X O O . . . |
$$ | . . . . . . . . . . . . . 2 X X O . . |
$$ | . . X , . . . . . , . . . . . . O . . |
$$ | . . . . O . . . . O . X . . . X X O . |
$$ | . . . . . . . . . . . . . . . . . X . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
FWIW, my own feeling is that White's threat, the atari,
![white 1 :w1:](./images/smilies/w1.gif)
, is too painful. And if Black extends to
1 instead of the two step hane, White can reply at
a.
Back to the mainline variation.
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[go]$$Bcm39 Mainline variation
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O X . . . . . . . . . . . . . . |
$$ | . O X O X . . . . . . . X . . X . . . |
$$ | . O X , X . . . . , . . . . . , . . . |
$$ | . . O X X . . . . . . . . . . . O . . |
$$ | . . O O X . . . . . . . . . . . . . . |
$$ | . . . . O O . . . . . . . . . . 5 0 . |
$$ | . . . . . . . . . . . . . . . 9 8 . . |
$$ | . . . . . . . . . . . . . . . 7 6 . . |
$$ | . . O , . . . . . , . . . . . , a . . |
$$ | . . . . . . . . . . . . . . . . c . . |
$$ | . . . . . . . . . . . . 4 2 . . . . . |
$$ | . . X . . . . . . . . d 1 O . . . . . |
$$ | . . . . . . . . . . . . 3 X O O . . . |
$$ | . . . . . . . . . . . . . . X X O . . |
$$ | . . X , . . . . . , . . b . . . O . . |
$$ | . . . . O . . . . O . X . . . X X O . |
$$ | . . . . . . . . . . . . . . . . . X . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
![black 43 :b43:](./images/smilies/b43.gif)
plays the one space pincer. With the support of
![white 40 :w40:](./images/smilies/w40.gif)
and
![white 42 :w42:](./images/smilies/w42.gif)
,
![white 44 :w44:](./images/smilies/w44.gif)
threatens to make a goodly territory in the right side.
a -
d are also possible After the top attachment of
![black 45 :b45:](./images/smilies/b45.gif)
, White crawls and connects underneath, making territory that way.
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[go]$$Bcm49 Mainline variation, continued
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . O X . . . . . . . . . . . . . . |
$$ | . O X O X . . . . . . . X . . X . . . |
$$ | . O X , X . . . . , . . . . . , . . . |
$$ | . . O X X . . . . . . . . . . 5 O . . |
$$ | . . O O X . . . . . . . . . . . . 2 . |
$$ | . . . . O O . . . . . . . . . 1 X O . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . . . . . . . . . . . . . . X O . . |
$$ | . . O , . . . . . , . . . . . 3 4 . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . O O . . . . . |
$$ | . . X . . . . . . . . . X O . . . . . |
$$ | . . . . . . . . . . . . X X O O . . . |
$$ | . . . . . . . . . . . . . . X X O . . |
$$ | . . X , . . . . . , . . . . . . O . . |
$$ | . . . . O . . . . O . X . . . X X O . |
$$ | . . . . . . . . . . . . . . . . . X . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]
After White connects,
![black 51 :b51:](./images/smilies/b51.gif)
intrudes once into White's territorial framework with sente, and the comes back and stablizes Black's wall.