Re: [gnugo-devel] Patch splee 5.5.1b revised

[SP Lee]

> Lee wrote:
> > arb:203
> >
> > 12 . O . . O . . . O . . O O O O O O . O 12
> > 11 O . . . . O . . . . . . . . . O X O . 11
> > 10 X O O + O X O O . + . . . . . O X X O 10
> >  9 X X O . O X X O . . . . O . O O X . X 9
> >  8 . X O O O X . X O O . . O O X O X . X 8
> >  7 . X X X X . . X X . O O X X . X . X . 7
> >  6 . . . . X X X . . X X X O X X X X O O 6
> >  5 . . X . . O . . . . X O O O O O O X . 5
> >  4 . . . X . . X . . X . X X X X O X X X 4
> >  3 . . . . . X O . X . . X . O O O O X . 3
> >  2 . . . . . . X . . O O . X O . O O O X 2
> >  1 . . . . . . . . . . . . X O X . O X . 1
> >    A B C D E F G H J K L M N O P Q R S T
> >
> > This is a complicated situation with up to 6 ko's in the lower right
> > corner. I don't think gnugo can really handle this situation until
some
> > time in the far future. T7 is a good move in that it makes the black
> > alive for sure and let white not easy to live. However, black is
also
> > not dead even playing on N3. For example, B:N3,W:T1,B:T7,W:T3,B:T5.
Or
> > B:N3,W:P7,B:R7,W:S8,B:T11.
>
> I don't think the life of black is a primary issue here, the question
> is how large external ko threats black needs in order to kill white.
> In particular N3 totally misses the point. This is not a capturing
> race but a question of whether white can make two eyes.
>
> > Both before and after patch, the ko_depth is reached during tactical
> > reading (attack n6). Surprisingly, the reading code after patch
> > generates less variations in this situation.
>
> Does the result of attack n6 change with the patch? Some reading
> results must have changed at least and the interesting question is
> whether those make sense.
>
> /Gunnar
>
>
After the patch "attack n6" is changed to 0. The move N3 is generated
through owl_attack N6. Before the patch "attack n6" is T7. However, I
guess it is passed by accident, since we are talking about whether white
can make two eyes for n6. It must be possible to tune owl later to get
correct result.


SP Lee