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Subject: Re: How many plies in chess game before hash table have some sense?

Author: leonid

Date: 15:59:54 12/08/99

Go up one level in this thread


On December 08, 1999 at 15:58:55, Bert van den Akker wrote:

>On December 08, 1999 at 15:10:16, leonid wrote:
>
>>On December 08, 1999 at 13:25:15, Vincent Diepeveen wrote:
>>
>>>On December 08, 1999 at 10:45:15, leonid wrote:
>>>
>>>>On December 08, 1999 at 10:17:47, Robert Hyatt wrote:
>>>>
>>>>>On December 08, 1999 at 08:32:48, leonid wrote:
>>>>>
>>>>>>Hello!
>>>>>>
>>>>>>How many plies chess game should have before hash tables could be of some use in
>>>>>>the chess game?
>>>>>>
>>>>>>Thanks,
>>>>>>Leonid.
>>>>>
>>>>>
>>>>>Three + captures should do it:
>>>>>
>>>>>Nh3 xxx Ng5
>>>>>Nf3 xxx Ng5
>>>>>
>>>>>and you avoid the rest of the 2nd search...
>>>>
>>>>Thanks!
>>>>
>>>>I tryed up to 5 plys and had no improvement. Something wrong with my logic. Will
>>>>go back and try 8 plies deep.
>>>
>>>there are always bugs in hashings... ...test it well, create at least
>>>a functoin that calculates the hashkey in the current position, and
>>>compare that with the incremental value. I bet there are some mistakes
>>>there!
>>>
>>>After that check go figure out how you store it. I've had nasty bugs
>>>when compressing a lot of info into a few bits.
>>
>>
>>I see that what you said have a good sense. I already killed one bug and rewrote
>>my hash logic for plies from 7 to 5. Still no speeding. Probably some bug more.
>>It sound so strange, since this part of logic apparently is so simple. Will
>>later go down to the minimax and see the difference. Alpha-beta can obscure
>>efficency of hashing.
>>
>>Leonid.
>>
>>
>>>
>>>>Leonid.
>
>
>Test your hash implementation with a very simple pawn endgame.
>You should see a gain of several 100% and your debuging will be simpler
>
>Success
>
>BvdA

Bingo! Your suggestion worked!
Rewrote my hash for plies between 7 and 5, but culd find nothing at the
beginning. Had one stupid bug. After kicking it out put only some 6 pieces on
board, where few pawns were in promotion mood. Difference was visible. Had
patience to try only two positions, was too happy to try more. In one speeding
around 3% and in the next great 54%.

Thanks!
Leonid.




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