[gnugo-devel] Inaccurate estimate_score

[Darren Cook]

The GTP commands shown in [1], give the output shown in [2]. It is black
to play. "final_score" is correct and the true score of this position is
60.5 to white if black moves next; 61.5 if white moves next.

I'm confused by the output of estimate_score; when the docs (manual
section 19.6) said upper/lower bound I was hoping for a reasonably
reliable possible range of scores (e.g. something like 59.5 to 61.5). Is
this a bug, or my misunderstanding of the docs?

It also seems the output of experimental_score is 2.5pts wrong for
black, 1 pt wrong for white. Again, is this a bug or my misunderstanding
of what it is doing?

Darren

P.S. Gnugo 3.6.


[1]:
showboard
final_score
estimate_score
experimental_score black
experimental_score white


[2]:
=
   A B C D E F G H J
 9 . X X . . . . . . 9
 8 X . X O O O . . . 8
 7 X X X O . O + . . 7
 6 . . X O . . O . . 6
 5 O O O . + . . O O 5
 4 . . X O O . . . . 4
 3 X X X O . O O O . 3
 2 . . . O . O . . O 2     WHITE (O) has captured 12 stones
 1 O O O O . . . . . 1     BLACK (X) has captured 1 stones
   A B C D E F G H J

= W+60.5

= W+59.5 (upper bound: 59.5, lower: 59.5)

= 58.0

= 60.5