Author: Robert Hyatt
Date: 21:06:42 06/15/02
Go up one level in this thread
On June 15, 2002 at 02:58:13, Uri Blass wrote: >On June 15, 2002 at 00:20:48, Robert Hyatt wrote: > >>On June 13, 2002 at 23:58:46, Christophe Theron wrote: >> >>>On June 13, 2002 at 09:13:43, Robert Henry Durrett wrote: >>> >>>>On June 13, 2002 at 06:00:13, Jorge Pichard wrote: >>>> >>>>>Hiarcs 8 was NOT made for slow computer such as an AMD 450 Mhz as the SSDF >>>>>decided to test it against Nimzo 8. >>>> >>>>What, exactly, causes this problem? >>>> >>>>Do other chess engines have this same problem too? >>>> >>>> >>>>Bob D. >>> >>> >>> >>>The problem is that the problem described above does not exist. >>> >>> >>> >>> Christophe >> >>Here we disagree significantly. >> >>One trivial case... Take a program that uses null-move R=2 or 3, and run >>it on a very slow machine. Then on a very fast machine. The slow machine >>will make significant blunders because the R=2 or R=3 depth reduction will >>be a killer. > >This problem can be easily solved if you do not use R=2 or R=3 when the expected >depth to search is small. > >I do not say that it is the best solution but the cost of one if command for the >speed of the program is close to nothing. > >Another obvious option to try can be not using null move pruning when the >remaining depth is small. > >I did not investigat the problem because I found that in the middle game R=2 was >productive for Movei in all time controls that I tried but it is possible that >even blitz on p800 is too fast(I tested it only on p800) and I need to test it >even at faster time control(I have no problem to do it because I have an option >to let Movei play faster by believing that it really has less time so I can make >it believe under winboard that it has only 12 or 6 seconds per game when it >really has a minute). > > >Note that Crafty on a slow p500 won a bullet tournament(1 minute per game Note that I don't consider a p500 to be "slow". The P6/200 was the machine that got me "over the hump" with R=2 null-move search. I was thinking more along the lines of a 486 or very early pentium, which (for me) had problems. ) >against other amateurs. > >see http://www.computerschachecke.de/Tournaments/Tables/BulletA.htm > >I guess based on that information that it does not make significant blunders >inspite of the R=2 or R=3 and the fast time control. Note that my early R=2 troubles were in blitz games on slow hardware. Most of the games I played on the chess servers in 1995 were blitz and that highlighted the slow hardware / R=2 problems... > >If you consider the fact that bullet on p500 is eqvivalent to slower time >control on slower machines then I suspect that your R=2 or R=3 is not a problem >even on very slow machines like 486 if you are interested on standard time >control. > >Uri R=2 wasn't so bad even on a P5/133, for 40/2hr games. It was the game/5 games that highlighted the problem. And good humans learned that the faster the time control, the worse Crafty (and other programs) did. IE Roman loved to play game/3 (3 0 on ICC) and he was very difficult back on that hardware...
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