Author: Robert Hyatt
Date: 21:51:17 09/17/05
Go up one level in this thread
On September 18, 2005 at 00:36:15, Mridul Muralidharan wrote: >On September 17, 2005 at 23:53:05, Robert Hyatt wrote: > >>On September 17, 2005 at 22:33:58, Vincent Diepeveen wrote: >> >>>On September 17, 2005 at 17:02:09, ALI MIRAFZALI wrote: >>> >>>Take a time control of 40 in 2 with pocket fritz against crafty without nullmove >>>and give crafty factor 1000 in nps extra. >>> >>>Deep Blue didn't use nullmove either. >> >>What does null move have to do with it? >> >>In 1996 there wasn't a computer on the planet that could beat deep blue. This >>is almost 10 years later. >> >>What is the point of this discussion??? >> >>Just a very lame attempt at starting a flame war, about a statement I supposedly >>made? (a statement I did _not_ make by the way)... >> > >I dont know about the flamewar part (I thought Vincent did not start the thread) >, but the 'without null move part' might be referring to the fact of deep blue >not using it. >Actually a good test would be : > >1) 1000x nps advantage >2) No null move >3) Use full singular extension as 'explained' by them. This is a completely worthless experiment. Take out my null-move search. Attempt to graft their singular extensions onto my program. What about my evaluation? My search extensions? How could one possibly add and remove bits and pieces of Crafty, to make something into the approximate skill of deep blue? Next, why is this important? My 1000x statement had nothing to do with null-move vs no null-move... > >I suspect (3) _will_ kill your search and keep the searchdepths much below what >the pocket fritz will get :) I don't think so. I had their full SE implemented in Cray Blitz. Its cost was almost 2 plies. But then tactically it was reaching very deep stuff to offset that. I've never found a workable SE that impressed me as "this is really good" when it comes to Crafty... On the quad opteron, my search depth would then probably drop to 13 plies. But then I get a factor of 1000X faster. My branching factor would be closer to 6 with no null-move, which would ramp me up by 4 plies without null move, or 10 plies with normal null move and a branching factor of around 2.0... > >So , even though Deep blue might have been invicible from programs of that age's >standards - it will get royally kicked around by even weak amateur programs of >today (bugfree ones ofcourse) running on modern hardware ! > >Regards, >Mridul again, based on what? Null-move is not generally credited with making a program 200 Elo stronger. I might one day run some decent-length games with null vs non-null to see what the actual rating difference would be for Crafty, then one might actually extrapolate what 1000x faster hardware would do by actually playing that time-odds match as well. Then we don't need to guess, speculate, or anything else... I'll remind you that a few years ago (I don't remember exactly when although you can find precise mention of the experiment here) I had the chance to play Crafty (I think on some quad box, which one I really don't remember) against Cray Blitz (less singular extensions, the version on the machine I had access to did not have that version) on a T932. Thing was searching about 7M nodes per second. It gave crafty a pretty good drubbing. And Cray Blitz on that machine could not touch deep thought, much less deep blue, based on actual OTB games against them at ACM events...
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