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Subject: Re: interesting endgame position

Author: Edward Screven

Date: 13:26:42 03/30/98

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On March 30, 1998 at 13:09:34, Jon Dart wrote:

>Recently my program "Arasan" played a game on FICS against
>"noro", and reached the following position:
>
>8/8/5R2/r5P1/8/p5P1/K5kP/8 b - -
>
>Here the computer played Rxg5 and eventually lost. It appears
>that Kxh2 draws (Crafty finds Kxh2 right away. The analysis
>goes Kxh2 g6 Rg5 Kxa3 Kxg3 Kb4 Kg4 Kc4 Kh5 Kd4 Rxg6).
>
>This isn't really hard, but it helps if the program knows
>the passed pawn is not dangerous even though the king is
>behind it. It looks to me like Crafty has special case
>code for just this ending (in EvaluatePassedPawns).
>Genius 5.0 also likes Kxh2 after a short search. I'm
>wondering if any other programs find this difficult.

i think that as long as you don't misevaluate passed pawns, then solving
this with a short search without any special knowledge should be easy.

my own program settles on Kxh2 after about 4.5 seconds at 12 ply.  i
have
an evaluation rule that detects uncatchable pawns, but i don't apply
it if the chasing side has pieces, so it poses no problems here.




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