Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Unusual Crafty behavior ?!

Author: Jesper Antonsson

Date: 09:58:51 11/18/01

Go up one level in this thread


On November 18, 2001 at 12:09:10, Jeff Lischer wrote:

>On November 18, 2001 at 10:03:15, piet de hoop wrote:
>
>>The next position occured in Diep versus Rebel Century 4 round 6 of the Dutch
>>Open Computer Chess 2001
>>
>>[D] 8/6p1/3k3p/8/3K4/7P/8/8 b - - 0 43
>>
>>The result was a draw, but for some computerprograms I tried, the evaluation was
>>from -1 to -3.4 pawn. (Fritz 6.0, Crafty,Yace)
>>
>>I expect that programs equipped with the right pawntable base have no problem
>>with this position, but i expected that programs without these tablebase while
>>calculating over 30 plys or more should give the right evalution?
>>
>>Or do i miss something?
>>
>>Piet
>
>When I tried this position with programs using all 3,4, and 5 piece tablebases
>they saw the draw immediately.
>
>The only oddity was Crafty. I was using Crafty 18.12 in WinBoard 4.2.3. When
>Crafty played White, it saw the draw in tablebases and moved immediately. When
>it was Black, however, it did not see the draw in tablebases. Instead it anayzed
>the position as it normally would and gave Black a 2-3 pawn advantage. Other
>programs (Yace, Gandalf) worked fine in WinBoard as both White and Black.
>
>Is this the intended behavior for Crafty or a bug? If it is intended, why?

I think it's intended. If you are white, you'll want to take the quickest route
to a draw. If you are black, you would either want to take the slowest route to
a draw or, perhaps better, search and play as usual (but only among drawn moves,
of course) in the hope that a human opponent will make an error and enter lost
tablebase space. :-)



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.