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Subject: Re: Crafty's 32-bit pawn hash collision figures?

Author: Dan Newman

Date: 18:13:35 12/06/01

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On December 06, 2001 at 17:29:43, Severi Salminen wrote:

>Hi
>
>How many collisions crafty gets on average using 32-bit keys? So how many nodes
>Crafty searchs on average to get 1 collision? I'm now using plain Visual C++ 6.0
>rand() with no hamming distance tests and I get about 80 collisions out of
>10'000'000 evaluations from initial position. I'd like to know if that is more
>or less than Robert and David were seeing. Funny thing was that first I searched
>about 5'000'000 nodes with no collisions, then I saw 40 collisions in a short
>time, then again no collisions and finally 40 more in a short time.
>
>Severi

I did this test on my program, Shrike, and got 62 collisions out of
66 million pawn hash probes with a 32-bit hash code, so I get about
1 collision per million probes.  This was on the WAC test suite and
so may vary in actual games...

-Dan.



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