Author: Johan Melin
Date: 00:54:23 09/17/00
Go up one level in this thread
On September 17, 2000 at 02:46:34, Larry Griffiths wrote: >I tried using my compilers rand() function but it was only generating >random numbers from 0 to 0x7fff. > >I ran 78 positions from the BWTC suite >and got over 10,000 mis-matches using my 64-bit hash keys. >I looked at my smallboards and they usually differ by a piece missing or in a >different position. My Piece table does not have zero or duplicate entries >and the random numbers in the piece table look good. >I built hashkeys using the two different smallboards and they do indeed >generate the same hashkeys. > >Maybe my hashkeys should be prime numbers? > >I will play around with random some more and see if it changes my mismatch >rate. > >Thanks Bob. > >Larry. With 10,000 mismatches something must be broken. How good are your random numbers? Try counting the bit-difference between all pairs of 64-bit keys. The average should be around 32 and the minimum above 12. /Johan Melin
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.