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Subject: Re: Counting attacked squares: how?

Author: Antonio Dieguez

Date: 11:52:08 01/24/02

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look at what you wrote:

a. counting...
b. counting...
c. counting...

most chess programmers assess mobility counting a numbers of squares, and then
multipling or doing an array look up?

since when I wrote mobility from the first time i use
(with the only difference that they are in spanish of course :))

mobilityBishop[]
mobilityRookNS[]
mobilityRookWE[]

so instead of a ++ or something while looping I do, for example for bishops:
mobility+=mobilityBishop[i];

of course mobilityBishop[i] is bigger when i is closer the center.

By the way I have anothers:

atacabilityBishop[][]
etc.

and in the second entry i put also the enemy king. Very cool.



>In an evaluation function, it makes sense to count
>and reward attacks to occupied and free squares.
>However, this can be done in several ways.
>Currently, I have the following data available
>and I assign bonus points for all these three
>count results:
>
>a. counting each square that I attack
>   at most once, regardless of the number of
>   attackers and defenders for that square.
>
>b. counting all my attacks to squares, so this
>   count is 2 for a square if both my knight and
>   my bishop (and no other pieces of mine) attack it.
>
>c. counting all squares that I control in the
>   sense that I attack it with a given piece
>   and the opponent defends it only with
>   more expensive pieces. For example, I regard
>   a square in my control if I attack it with a pawn
>   (and possibly other pieces as well), while the
>   opponent may defend it with as many
>   non-pawn pieces as he likes.
>
>If you have a opinion (preferably based on experience
>and chess knowledge) about the relative merits of
>these counts in an eval function, please indicate
>this by giving weight factors.
>For example:
>c 3, a 1, b 0 (if you regard b as useless).
>(I hope your answer will not be a 0, b 0, c 0 -;)
>
>Leen



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