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Subject: Re: Hash Collisions (Dan)

Author: Larry Griffiths

Date: 11:33:03 02/23/99

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Dan,

I read your post on hash collisions.  I have tried some hamming distance
code and I see little difference when compared to generating random
numbers.  I have been thinking of writing code that does what you said
where 64 bits must have 32 bits (or 50%) turned on in each number.  I also see
where there are many references to the 12 pieces times 64 squares = 768
hash codes.  Since the a Bishop can only control 32 possible squares and
there are 4 bishops, then 128 of the 768 are unused.  Also, Pawns only
use 48 squares for each side, so 32 squares are unused by pawns.
768-128-48 leaves 592 hashcodes for the piece square table.
Food for thought?  Errors in my thinking?

Larry.



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