Re: Loss over Perpetual

Mike Roberts wrote:
> There seems to be a bug in GNU Chess 5.0 which caused it to lose the
> attached game (with 23... Kh8) rather than settle for a draw by
> perpetual check with (23...Kf8 24. Qe7+ Kg8 25. Qe6+ Kf8 and so on).  It
> seems strange that the program chooses to give white mate in two rather
> than settle for a draw.

Thanks Mike,

seems to be a problem even when the relatively recent "ponder" feature
is disabled.

It does consider Kf8 best to a depth of 32768 ply, before playing Kh8,
and does seem to play Kf8 in some cases (first occurrence). So some sort
of search termination problem.

I know there are some edge cases when mate is imminent for one side or
other, where the code goes wrong, but this looks like a useful test case.

 Simon

_______________________________________________
Bug-gnu-chess mailing list
[email protected]
http://lists.gnu.org/mailman/listinfo/bug-gnu-chess

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (GNU/Linux)
Comment: Encryption...is a powerful defensive weapon for free people.
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFHJPF7GFXfHI9FVgYRAmusAJ9FVgg5NPBZ475U8o7zC11hvugSCwCgo+YD
1dfM2or1L36t+HTrrlbWHq0=
=cEKd
-----END PGP SIGNATURE-----