Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Deep Blue kns compared to kns on my 3066mhz system

Author: Sune Fischer

Date: 12:13:14 07/23/02

Go up one level in this thread


On July 23, 2002 at 13:53:34, Uri Blass wrote:

>On July 23, 2002 at 12:46:44, Sune Fischer wrote:
>
>>On July 23, 2002 at 11:48:02, Uri Blass wrote:
>>problem.
>>>
>>>The evaluation of the top programs of today is better relative to the evaluation
>>>of some years ago.
>>>
>>>Uri
>>
>>I think Deep Blue had a lot of knowledge compared to the micros of 1997.
>>
>>It evaluated:
>>*) concepts such as square control
>>*) pins
>>*) x-rays
>>*) king safety
>>*) pawn structure
>>*) passed pawn
>>*) ray control
>>*) outposts
>>*) pawn majority
>>*) rook on 7th
>>*) blockade
>>*) restraint
>>*) color complex
>>*) trapped pieces
>>*) development
>>*) and so on...
>>
>>Example of kingsafety:
>>"Before the king castles, the system computes three king safety evaluations, one
>>for king-side castling, one for queen-side castling and the base value for
>>staying in the center. Each of these king safety evaluations takes into account
>>the types of pieces attacking, the soundness of the king's shelter, presence of
>>attacking pawns, color complex around the king, and os on. The final king safety
>>evaluation is a weighted linear combination of the three king safety
>>evaluations."
>>
>>-S.
>
>Having more complex evaluation does not mean having
>a better evaluation.
>It may mean that there is more danger of bugs so you may have worse evlauation.

To be honest, I think your reasoning is a bit weird ;)

>I also believe that linear combination of three king safety
>evaluations is not a good idea.
>
>If the king is safe only in the center then I do not care about
>the exact king safety in the king side or the queen side because I am not going
>to go to there.

Well, that is what an evaluation is supposed to do, it's up to the search to
choose the whether or not to do the castle based on the alternatives
investigated in the search tree :)
I don't think I understand your objection to this, you can't evaluate 100%
accurate, its a sum of terms leading to an overall score, that is how
evaluations work AFAIK. If you think eg. an open file towards your king is very
bad, you can always give that a huge penalty.

>If the king is safe only in the king side then
>I care if I can castle there but not about average of evauations.

I don't follow.

>
>Uri



This page took 0 seconds to execute

Last modified: Thu, 15 Apr 21 08:11:13 -0700

Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.