Author: Dann Corbit
Date: 14:04:14 02/18/99
Go up one level in this thread
On February 18, 1999 at 14:45:59, Inmann Werner wrote: [snip] >What does this mean in particular for chess programming? > >I use one hashingadress between 0 and 2000000 for the hash adress and one >extra calculated long int for verification. Each of the both hashcodes result >out of 2 different sets of 64 long int numbers. >How high is the probability of a collision in this case, and do you use the >same algorithm? I think we have to know what hash we are using in order to talk about collisions. For instance, I could choose a hash for people's names which uses the first six letters as base 26 numbers. This would probably be a rather bad hash, because people's names are not spelled at random, and because we are likely to receive them already in order (unless, for some reason we *want* collisions). It seems that most chess programs use Zobrist hash. I think it would be interesting to count collisions for opening, early middle game, mid-game, endgame, and late-endgame and see if the proportion stays the same as the board clears. I am fairly sure that it will not be exactly as probability would dictate if we had a perfectly random distribution of positions. It might also be interesting to investigate the properties of other hashing algorithms.
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.