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Subject: Re: History Heuristic

Author: Renze Steenhuisen

Date: 08:15:43 03/16/04

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On March 16, 2004 at 11:04:39, Vincent Diepeveen wrote:

>On March 16, 2004 at 04:41:40, Renze Steenhuisen wrote:
>
>It seems to differ from program to program.
>
>In diep it doesn't work at all.
>
>I tried many different forms of keeping track of the HH table. There is no need
>for just [64][64] there is many different forms possible. Like for each side
>makes already more sense.
>
>In diep the general killermove also hardly works. HH is probably even more a
>'general overal killer'. In diep basically local killers who continuesly get
>replaced work very well.
>
>All big slow global stuff just doesn't work for DIEP.
>
>I had the same result for my draughts program Napoleon.

Yeah, I read your previous post on this topic from the archive but thanks
anyway! I have tried some different things, but I am a bit puzzled.

I got very good numbers for gain in move-ordering for shallow searches (say 5-7
ply), so I tried 2 things:



>>Hi all!
>>
>>I did some measurements on my move-ordering, and it seems that the positive
>>effect of the History Heuristic wears of with increasing search depth? Is this
>>observed by others as well or am I doing something awfully wrong here...
>>
>>
>>History Heuristic:
>>
>>    int table[64][64];
>>
>>    every time the 'best move' was found (either fail-high or all moves
>>    searched) I do:
>>           table[from][to]+=remaining_depth*remaining_depth
>>
>>    The non-capture moves are sorted in History Heuristic order.
>>
>>Cheers!
>>
>>Renze



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