Author: martin fierz
Date: 02:14:03 10/31/03
Go up one level in this thread
On October 30, 2003 at 16:27:18, Dieter Buerssner wrote: >You might also enjoy to read http://www.chess-archive.com/ccc.php?art_id=190318 >which shows some experiment about collisions, and that they are really not worth >to mention as a practical problem in typical situations. I just tested "Gerd's" >PRNG (close to the start of this thread). I is really bad as a PRNG. For >example, a simple test that tries to find out how many lower case letter that >PRNG will find. When we assume that 'a' is 0, 'b' 1, etc. and we take the lower >8 bits of that PRNG. One would assume, (26 letters - 256 possibilities for lower >8 bits), that one would find one word in 1000 calls to the PRNG. But that PRNG >is really bad - it won't find even one word after letting it run for years (That >PRNG will never output 3 numbers in a row, where the last 8 bits are < 26). >Still - it will work nicely for "our" Zorbrist type hashing. > >Regards, >Dieter hi dieter, interesting post that you point to there. i once did something similar in my checkers program but i've forgotten my results - they were definitely similar to yours though. i just masked of a number of bits in my hashkey. it's pretty surprising that even a 12-bit hashkey will suffice for practical purposes! BTW you mention that you do hashing in QS in yace. since i don't do this in my program: how much does this help? should i try? (of course the answer to this question is yes, as one should always try... but how much in % would you estimate that you gain by using hash in QS?) cheers martin
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.