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Subject: Re: Pawn Hash Collisions in Crafty

Author: Sune Fischer

Date: 02:40:54 12/06/01

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On December 06, 2001 at 05:06:49, David Rasmussen wrote:
>No it doesn't. How do you know? Have you done any tests yourself? No. You just
>theoreticize. And falsely too, since my findings have been confirmed.

I have too, didn't you read my post followup?

>>Well for pawn tables I believe this is the same. Since there are so few
>>different posistions, even one collision could mean a thousand collisions
>>because it is reused so many times.
>>
>
>Apparently not. Crafty has this problem. Still, it is pretty strong. Now that
>Bob changes back to 64-bit keys in light of my findings, I guess it will only
>get stronger, but the question is "how much stronger?".

Yes I read that he he "confirmed" your results, but if you really had 300
collisions you would have a really poor pawn eval(). I think some things has
changed in crafty since last Robert tested, perhaps a bad PRNG?
32 bits is enough, I'm pretty sure of it (both theoretical and emirical), unless
you have too many positions.

>>Huh?
>>Neither me or Hyatt can confirm your findings, and since Bruce is also using
>
>Yes, Hyatt has.

Give him more time, perhaps he will find the bug :)



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