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Subject: Re: Management Of Evaluation Knowledge - How Does Crafty Do It?

Author: Alessandro Damiani

Date: 07:03:51 07/23/00

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On July 22, 2000 at 22:21:19, Robert Hyatt wrote:

>On July 22, 2000 at 04:47:14, Graham Laight wrote:
>
>>Looks like Ed doesn't want to continue this thread any more, which is
>>understandable, because if he does, he could end up revealing more about how he
>>does evaluation than he really wants to.
>>
>>So - if anyone reading this knows how knowledge in Crafty is organised, could
>>they post an overview here, please, so that we can continue this thread?
>>
>>Thanks for your help with this.
>>
>>-g
>
>
>This is not easy to answer.  But here is a rough explanation.
>
>First, there are several knowledge 'modules' that are called when
>appropriate. IE before both sides have castled and developed all pieces,
>there is an EvaluateDevelopment() modules that is called.  Once this has
>done its job, it is disabled for the rest of the game.  There are similar
>modules for mating the opponent, evaluating passed pawns, evaluating
>passed pawn races, and so forth.  And they are only called when it is
>appropriate.
>
>The rest is more complex.  There are many 'major' terms...  king safety,
>endgame outlook (ie passed pawns, outside passed pawns, pawn majorities,
>and so forth).  These terms are phased in based on remaining material. IE
>king safety is multiplied by using three factors;  1 is the pawn structure
>around the king, 2 is the pieces of the opponent and how dangerous they
>appear to be (how close and how many are close) and 3 remaining material.
>As material is removed, king safety scores are scaled down.
>
>By the same token, as material is removed, endgame predictors are scaled
>up (ie an outside passed pawn becomes more valuable).
>
>This is all what I call "third order evaluation" since three complex factors
>are used to compute a number...
>

I think you took care of smoothness (SNAC)?

Alessandro



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