Re: Loss over Perpetual

[Simon Waters]

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

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