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Subject: Re: Tablebases Again

Author: Bernhard Bauer

Date: 02:02:09 10/12/98

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On October 11, 1998 at 01:37:52, Bruce Moreland wrote:

>
>On October 10, 1998 at 21:25:25, James T. Walker wrote:
>
>>I tested Crafty15.20 tonight and it solves the problem instantly.  I also tested
>>the following computers/programs. ALL solved the mate instantly.
>>Fritz5.0,Rebel Decade 2.0,Rex2.3,Fidelity Mach3,Fidelity Mach IV,M-Chess Pro 3.5
>>M-Chess Pro 5.0,Genius 4.0, Genius 2.0,Kasparov's Gambit,CM4000,CM5000,CM5500
>>and my handheld Mephisto Marco Polo(USCF about 1800).  I do not have a single
>>program/computer that does not solve this instantly.  Maybe the creator of JR.
>>should take a look at this problem.
>>Jim Walker
>
>After you check to see if they find the mate, please also check to see if you
>can play out the main line by making each move.  Also, check to see whether it
>works with colors reversed.  I bet that there are cases where programs will call
>the game a draw, without executing the mate, or without allowing you to execute
>the mate.
>
>bruce

Yes, we should be carefull in this type of position.
For the following position:
White: Kc8, Bg8
Black: Ka8, Ba7
White to move
FEN: k1K3B/b/8/8/8/8/8/8 w
Crafty 15.20 will move Bh7 instead of mating with Be5# and it will tell us
game is a draw due to insufficient material. The learning is wrong too.
Crafty says: learning position, wtm=1  value=-66

By the way, the "insufficient material feature" has further consequences.
For the following position, which is a mate in 6 Crafty has no clue.
FEN: 8/1k1K4/8/8/1pN5/1N6/8/8 w

Kind regards
Bernhard



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