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Subject: Re: In the generate_move function...

Author: leonid

Date: 06:27:18 12/19/99

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On December 19, 1999 at 02:56:02, Tom Kerrigan wrote:

>On December 18, 1999 at 21:46:17, leonid wrote:
>>It is very interesting that I found many times that people indicate the usage of
>>"illegal moves" as very beneficial. Was able to use them only in the ply zero.
>
>Can you restate this? I can't think of a time when illegal moves would be
>beneficial...

No, they can sometime but very little. For the sake of clarity will say what I
mean by "illegal move". Maybe my definition is wrong. I am not used to the
normal terminology in chess programming. For me "illegal move" is every move
that is found without checking if the king will be under the fire. Usage of
"illigal moves" in the ply zero gave me somewhere around 1.5%, if my memory is
right. I remember that I put it there mainly because I was able for the first
time count the number of positions per second that my logic was able to see.
Before it was only guessing.





>>Today read one idea more that looked to me very promissing. Tryed it but, beside
>>light lost in speed, found nothing. It was the statement indicating that when
>>you have some enemy piece under the fire, take it first with your less valuable
>>piece. Found no improvement when put this idea to work. Strange! Idea sound to
>
>This method (MVV/LVA) will slow your program down in terms of nodes per second,
>but it should radically increase the effectiveness of alpha-beta cutoffs. If it
>doesn't, maybe there's something wrong with your search algorithm.
>
>-Tom

I tryed what in your text I see as LVA, and this fail to give me some speeding.
Idea was new for me. Was not able apparently to find it before. From the other
side, MVV was obvious to me very soon and it is responsable for much of the
speeding in my alpha-beta logic. To be sincere, have no idea if I can even speed
more my logic. Sometime I have the impression that my logic is very slow as such
and  sometime that it is right on its place. There is no way to try the other
game for raw speed in positional logic, in order to make the comparison. Only
when logic look for mate that you can compare different chess games speed with
100% security.

Leonid.




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