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Subject: Re: A question for all chess programmers!!!

Author: Dann Corbit

Date: 16:41:26 01/04/99

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On January 04, 1999 at 19:02:43, Ivo Fasiori wrote:
>Why chess programs are so bad at endgames?
>
>Why, for example, NO CHESS SOFTWARE can see a draw
>in the following well known draw positions?
>
>8/6kP/5N2/5K2/8/8/8/8 w - - 0 1
>
>5k2/6r1/4Q3/8/8/8/8/7K b - - 0 1
>
>3k4/3p4/4r3/3K4/8/1Q6/8/8 w - - 0 1
>
>Is it an evaluation problem? Or an algorithm problem?
>
>Would it be necessary to write special routines
>for endgames (or they exist already?)?
How long did you let the programs run?  Which programs did you try?  In what
mode were you operating the programs?  If you are doing traditional EPD
analysis, then the programs are simply searching for the best next move, not
trying to complete the game.  In each case, did the program respond with the
wrong move or the right one?  Your second position, for instance, seems to have
only one sensible response (Crafty decides on Rh7+ in less than one second).
Could it be that your programs stopped analyzing after finding what seemed to
them to be the best or only feasible choice?  Some Crafty output (note: a
bazillion other intensive things were running on this machine...)
Crafty sees a drawish eval for one of the three, but thinks it is kicking-tail
for the other two (by order of ce magnitude):
5k2/6r1/4Q3/8/8/8/8/7K b - - acd 4; acn 57; acs 1; ce -66; pv Rh7+; c0 clearly
drawish
3k4/3p4/4r3/3K4/8/1Q6/8/8 w - - acd 15; acn 91307102; acs 772; ce 340; pv Qb8+
Ke7 Qg3 Kf7 Qg4 Ke7 Qg7+ Ke8 Qg8+ Ke7 Qh7+ Kd8 Qh8+ Kc7 Qh2+ Kb7 Qh7 Kc7 Qc2+
Rc6 Qh2+ Kd8 Qb8+ Ke7 Qe5+ Kf7 Qe4; c0 at 7.5 fullmoves, still looks good for
white
8/6kP/5N2/5K2/8/8/8/8 w - - acd 36; acn 157709930; acs 770; ce 691; pv Ke6 Kh8
Kd6 Kg7 Ke5 Kh8 Ke6 Kg7 Kd6 Kh8 Ke5 Kg7 Ke4 Kh8 Kd4 Kg7 Kc5 Kh8 Kc6 Kg7 Kd5 Kh8
Kc5 Kg7 Kc6 Kh8 Kd5 Kg7 Kd4 Kh8 Ke4 Kg7 Kf5 Kh8 Ke6; c0 even at 18 fullmoves
looks like white is in total command -- are you sure it is a forced draw?




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