Re: [gnugo-devel] a capturing race

[SP lee]

>
> In the SGF below, here's the position before move 207:
>
> showboard
> =
>    A B C D E F G H J K L M N O P Q R S T
> 19 . . . O X . . . . . . . . . . X . . . 19
> 18 . . . O X O . . . . . . X . O X O . . 18
> 17 . X X X O O O . . X X X O O O X O . . 17
> 16 . . O X X X O . . O X O O X O X . O . 16
> 15 . . O . O O . O O X . X X X O X X O . 15
> 14 . O . O . X O O X . X . X O X X O O . 14
> 13 . X O . O . X X X X . X X O O O O X O 13
> 12 . X O . . X . . . . X O O O O X X X . 12
> 11 . O . O . . . . . . X X X O X X X X X 11
> 10 . O . O . . . X . X . . X O X O . X . 10
>  9 . X O O . . . . . . . O X X O . O . . 9
>  8 X . X X O . X . . . X X O O O O X X X 8
>  7 . X . . . . . . X . X O O O O X . . . 7
>  6 . X O O O . . X O O O . . . O X . . . 6
>  5 . . X X O . . X X X X O O O O X . . . 5
>  4 . . . X O . . X O O O X X . O + X . . 4
>  3 . . . X O . O O . O X . . X O O X . . 3
>  2 . . . . X X . . . O X . X . O X X . . 2
>  1 . . . . . . . . . . . . . . . . . . . 1
>    A B C D E F G H J K L M N O P Q R S T
>
> In the game, White plays to R19 as a forcing move before returning to the
> capturing race underway at the bottom. GnuGo as Black ignores this,
> tries to save the group at the bottom, and ends up losing both. (This is
> 3.4, but the current version has a similar idea.)
>

There happens to be a good move for black on move 210, i.e. O-2. So black's
lower group becomes alive and no capture race is necessary. I'm not sure if
gnugo already saw this move.


SP Lee