Computer Chess Club Archives


Search

Terms

Messages

Subject: Re: Hashkey collisions (typical numbers)

Author: Renze Steenhuisen

Date: 05:29:55 04/07/04

Go up one level in this thread


On April 07, 2004 at 07:38:54, Thorsten Greiner wrote:

>
>>I have two counters for calculating my hashkey-collisions:
>>   hashmove_requested: every time I have a hashmove and I am going to check
>>            whether it is a legal move.
>>   hashmove_illegal:   suggested hashmove from the TT was not legal, and
>>            therefore a hashkey collision has to be occured.
>>
>>100*((double)hashmove_illegal/hashmove_requested) gives my number... 0.03
>
>Your algorithm to determine hash collisions seems ok, iff you
>
>- hash the side to move into the hashkey
>- OR use separate hash tables for white and black
>- AND don't count null moves as illegal moves (if you store them)

I will check the incremental hashkey with the freshly generated hashkey at every
position... (I will get back on it soon)

- I don't store NULL-moves
- When BLACK is to move I use the bit-wise inverse of the hashkey
- And when a NULL-move is returned it is not counted

Renze




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.