Author: Larry Griffiths
Date: 13:56:51 02/25/99
Go up one level in this thread
On February 25, 1999 at 15:24:04, Peter McKenzie wrote: >On February 25, 1999 at 09:21:57, Larry Griffiths wrote: > >>On February 25, 1999 at 06:53:37, Vincent Diepeveen wrote: >> >>>On February 24, 1999 at 21:39:53, Larry Griffiths wrote: >>> >>>>On February 24, 1999 at 18:41:24, Vincent Diepeveen wrote: >>>> >>>>>On February 24, 1999 at 17:48:23, Larry Griffiths wrote: >>>>> >>>>>>Greetings CCC Chess Programmers! >>>>>> >>>>>>How long does it take your chess programs to go 10 full plys >>>>>>from whites opening move of E2-E4? >>>>> >>>>>few seconds, depending upon selectivity it can take up to 1 minute. >>>>> >>>>Hi Vincent, >>>> >>>>What do you mean by selectivity? My program ran for 22 minutes >>>>(Using a hash table and alpha-beta pruning with a killer heuristic). >>>>I have used the CM6000 auto-analysis with 10 seconds per move and have >>>>seen it go 10-14 plys deep at times. It sounds like your program is >>>>also very fast. Do you mean that you go a few full plys and then >>>>do secondary searches? >>>> >>>>It sounds like I would have to improve the speed of my program by >>>>100 to 1000 times to catch up with you fellows. >>>> >>>>Larry :-) >>> >>>I get 20k nodes a second at a PII-450. >>> >>>But about getting deeply. >>>a) improve move ordering >>>b) use nullmove >>> >>>especially a is important when using b >> >>Thanks Vincent. >> >>My current move order is: >> HashTable, One Killer move, Capture GT, Capture LE, and then the rest >> of the moves. I have read that using a history killer is better than >> just saving the last cut-off move. I want to implement it but >> I have to make major changes to the code to do this. > >Put captures in front of killers, this should significantly reduce your node >count straight off. > >What sort of capture ordering are you doing? Unless you are using a static >exchange evaluator, the best is probably MVV/LVA which stands for Most Valuable >Victim, Least Valuable Attacker. This means, first order by the value of the >piece you are capturing then by the piece doing the capturing. King is a >special case, it is treated as the least valuable attacker. > >So you'd try captures in this order: > >KxQ, PxQ, NxQ, BxQ, RxQ, QxQ, KxR, PxR, NxR, BxR, RxR, QxR, KxB, PxB, etc > >cheers, >Peter > >> >>Larry. Peter, You caught me! The Capture GT is MVV and the Capture LT is LVA, but I am not ordering within MVV or LVA if more than 1 capture exists. I will do some tests with the killer after the captures. Thanks a million! Larry :-}
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