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Subject: Re: Crafty endgame position

Author: Terry McCracken

Date: 14:49:42 04/07/02

Go up one level in this thread


On April 07, 2002 at 16:57:14, Uri Blass wrote:

>On April 07, 2002 at 14:52:21, Terry McCracken wrote:
>
>>On April 07, 2002 at 14:41:20, Mike Hood wrote:
>>
>>>On April 07, 2002 at 14:23:46, Terry McCracken wrote:
>>>
>>>>On April 07, 2002 at 11:57:18, Robert Hyatt wrote:
>>>>
>>>>>On April 07, 2002 at 10:41:27, Michael Fuhrmann wrote:
>>>>>
>>>>>>[D] 1b6/8/8/7p/6k1/6P1/8/6K1 w - - 0 1
>>>>>>
>>>>>>Crafty, without tablebases, scores this as about -4.5 for white. Shouldn't the
>>>>>>score be 0.0?
>>>>>
>>>>>
>>>>>This excites some sort of bug that I haven't seen.  the static evaluation for
>>>>>this position is 0.00, but the search produces some sort of position where the
>>>>>draw recognition fails...
>>>>>
>>>>>I'll look at it...
>>>>
>>>>Don't be too hard on yourself Dr. Hyatt, Fritz 7 although close to accurate
>>>>gives an eval of -0.81 pawns and Shredder is a little worse than Crafty at
>>>>-4.96, well Chess Tiger 14.0 is "out to lunch" between -12 to -11+ pawns!
>>>>
>>>>Sorry Christophe! You need to fix this problem before you release Chess Tiger
>>>>15.0.
>>>>
>>>>Terry
>>>
>>>This is a matter of opinion. I think that today's chess programmers have the
>>>right to assume the use of 5-piece tablebases. The time spent tweaking the
>>>algorithms for cases like this would be better spent on writing better
>>>algorithms for middlegame analysis.
>>>
>>>But it's the programmer's own decision. Maybe he wants to solve this problem
>>>anyway for the sake of his own intellectual achievement.
>>
>>
>>It is my opinion, but I feel _all_ aspects of the game need to be thoroughly
>>covered, Opening, Middlegame, and Endgame.
>>
>>It's a _tough_ job but I feel it needs to be done.
>>
>>Terry
>
>Non tablebase position seems to be more important and the general rule says
>that the stronger side has chances to win in similiar positions that are not
>tablebases positions.
>
>A program that says by static evaluation without tablebases 0.00 may say 0.00
>also in the following position rhat is not a draw.
>
>[D]1b6/8/8/7p/7P/6Pk/8/6K1 w - - 0 1
>
>Uri

Interesting Uri....yes White is "Dead Lost" if 1.Kf1..Ba7!++ if 1.Kh1..Ba7!
2.g4..hxg4 3.h5..g3 4.h6..g2#

Fritz 7 sees this instantly! It considers 1.Kf1..Ba7 with nearly a negative 5
pawns. If I were to let it go really deep it might find a long mate, I'm not
certain.

Terry



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