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Subject: Re: Material Values

Author: Uri Blass

Date: 00:45:55 01/22/02

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On January 22, 2002 at 02:41:23, martin fierz wrote:

>On January 21, 2002 at 03:59:55, David Rasmussen wrote:
>
>>On January 20, 2002 at 19:21:07, martin fierz wrote:
>>
>>>On January 20, 2002 at 16:21:02, David Rasmussen wrote:
>>>
>>>>
>>>>I am not talking about things that depend on a lot of other stuff. Evaluation
>>>>should take care of this. I am talking about Crafty that explicitly checks for
>>>>some material special cases _and nothing else on the board_, and decides if it
>>>>should give a penalty/bonus. I say that I think it can be done with the values
>>>>alone. Why not?
>>>>
>>>>/David
>>>
>>>because all your examples above depend on a lot of other stuff maybe? that's the
>>>point i tried to make in my post: a single rook with pawn vs knight and bishop
>>>can have good chances in this pure endgame (+ a few more pawns each). in the
>>>middlegame nearly never. how would you want to encode that in your material
>>>values?
>>
>>I don't want to do that. I would want to add evaluation terms for that. Isn't
>>that necesary with 1,3,3,5,9? Yes it is. What I am suggesting is not catching
>>_all_ cases with material values, just to catch some more than one can with
>>1,3,3,5,9. And have fewer evaluation terms for special cases. I believe that is
>>possible. At least I haven't seen any arguments against it. It seems that most
>>people in this thread has misunderstood my question altogether.
>>
>
>i dont misunderstand your question. but there are lots of things you must take
>into account for the material evaluation, *regardless* of what your base values
>are. at least if you want to write a decent program. so in some sense, your
>question has no answer, because whatever your base values are, you should add
>some special cases. however, the reason that 1,3,3,5,9 is "magical" as you term
>it is that these are in fact very good values for the pieces. every beginner's
>chess book has these values in.
>i'm pretty sure that these values represent the values of the pieces as
>accurately as possible under the constraints pawn=1, values only integers. and i
>think these two conditions just come from the fact that when you write a chess
>book for beginners, you want it to be simple. if you were to ask me, i would
>rather go for 1,3,3.2,4.5,8.5 for PNBRQ, which i think is definitely better

If you ask me I prefer
1,3.4,3.5,5,9.3 but the idea of chess books was not to explain things to
computers and it is more simple to remember 1,3,3,5,9

Uri



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