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Subject: Re: Material Values

Author: David Rasmussen

Date: 07:25:50 01/20/02

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On January 20, 2002 at 10:12:28, Uri Blass wrote:

>On January 20, 2002 at 09:41:48, David Rasmussen wrote:
>
>>On January 20, 2002 at 09:29:24, Severi Salminen wrote:
>>
>>>On January 20, 2002 at 09:01:50, David Rasmussen wrote:
>>>
>>>>There must be a value system of material that takes care of all special cases.
>>>>
>>>>1,3,3,5,9:
>>>>
>>>>Has the following problems:
>>>>3 pawns for bishop or knight is almost always a bad idea.
>>>>2 knights/bishops for rook and pawn is almost always a bad idea.
>>>>2 rooks for queen is often not a good idea.
>>>>3 knights/bishops for a queens is often not a good idea. Then again, often it is
>>>>:)
>>>>
>>>>What is your best bet?
>>>
>>>And sometimes a Bishop is better than a knight. So:
>>>
>>>P=1, B>N>3*P, R+P>2*B, Q>2*R and Q>3*B.
>>>
>>>So maybe P=1, N=3.2, B=3.4, R=6, Q=13?
>>>
>>>Severi
>>
>>I don't want to score bishop higher than knight. It depends on dynamic factors
>>that should be in evaluation anyway. I just want to avoid extra code to evaluate
>>special cases, as Crafty does. I think it is possible.
>>
>>/David
>
>There is no answer for your questions.
>
>It is even not possible to know what is the meaning of P=1
>because the value of the pawn is dependent in the square of the pawn.
>
>If you do not use piece square table for pawns then your program may be weak
>
>If you use piece square table for pawns than P=1 is eqvivalent to P=1.2 when you
>only change the piece square table for the pawns.
>
>Uri

Look, I am not talking about perfect evaluation here. I am talking about a
mature evaluation function, but instead of evaluating material special cases
(three pawns for a bishope etc.) as crafty does, I think all of these _material_
special cases can be done with material values alone. All the other evaluation
stuff will still be there.

/David



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