Re: [gnugo-devel] Scoring problem

[Gunnar Farneback]

Dan wrote:
> The aftermath code computes the score of this game
> incorrectly.

As usual a problem where the owl reading acts weirdly, finding a bogus
defense for a dead group, but only after the *opponent* has
strengthened his position locally.

> Correct is W+53.5 points. This is the score found
> by --score last or --score end. The game record
> shows W+27.5 points which was obtained by calling
> the gtp function final_score, based on the aftermath
> code. If you load the file with --score aftermath you
> get yet another score, 29.5 points.

No idea about the difference between 27.5 and 29.5. When loaded from
the game record both final_score and --score aftermath say W+29.5.

The simplest solution for the owl problem is the appended patch,
causing all scoring methods to agree on W+53.5. Use it in 3.4 if you
want, or postpone it for 3.5.1. I haven't checked what it does to
regressions or node counts.

/Gunnar

Index: patterns/owl_attackpats.db
===================================================================
RCS file: /cvsroot/gnugo/gnugo/patterns/owl_attackpats.db,v
retrieving revision 1.90
diff -u -r1.90 owl_attackpats.db
--- patterns/owl_attackpats.db  4 Jul 2003 11:50:28 -0000       1.90
+++ patterns/owl_attackpats.db  16 Jul 2003 21:34:03 -0000
@@ -412,7 +412,7 @@
 Pattern A204
 
 ??O??              second line block
-..*Y?
+?.*Y?
 .....
 -----