Re: [gnugo-devel] Strange choice of move

[Gunnar Farnebäck]

Regis wrote:
> First, thank you for making gnugo.
> I take great pleasure to play with gnugo for plays on 9x9
> since it often proposes me hard problems and I'm not an experienced player.
> 
> It sometimes seems to make strange choices and i was asking myself if it 
> wasn't a bug.
> 
> I've notice it can choose to expand (move 40), and then abandon its new 
> territory (move 50).
> I send you a sgf file which illustrates the fact.
> Well, I guess it should have play 40 in J5 instead if its right isn't secure.
> I suppose you'll see what i mean.

Thanks for providing the position.

Actually there is no problem with the eyespace at move 40 but move 48 at
A7 is simply a blunder. Before that move the A6 string can be captured
and must be defended, preferrably by playing J3. After white A7 black
can and does capture with A8 and at move 50 white can't do anything
better than retreat to J3.

   A B C D E F G H J
 9 . . . . . . . . . 9
 8 . . . . X . . X . 8
 7 . X X X O X X . X 7
 6 O O X O O O O X . 6
 5 O . O O O . . O X 5
 4 O O X X . O . O X 4
 3 O X X . X X O . . 3
 2 X . . X . X O . . 2
 1 . . . . X O O . . 1
   A B C D E F G H J

/Gunnar