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Subject: Re: qsearch questions

Author: Jon Dart

Date: 09:36:44 12/04/02

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On December 04, 2002 at 03:43:09, Bas Hamstra wrote:

>It is not the same IMO. I think Jon means this: suppose Eval is below alpha.
>Then in Crafty you calculate Delta=Alpha-Mat-Margin. However more accurate might
>be Delta=Eval-Margin. IE you prune based on Eval rather than material.
>I tried this, and the result is it will throw out less captures while I see no
>noticable improvement in accurracy.

Yes, this is what I meant. Note that if you do an early exit from the scoring
function (lazy eval) then you need to adjust that if using this technique. E.g.
if you stop when you know the score is below alpha, that's wrong now, because
the amount the score is below alpha matters (cutting off early if you are above
beta is not a problem).

--Jon





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