Author: Mridul Muralidharan
Date: 22:19:17 09/17/05
Go up one level in this thread
On September 18, 2005 at 00:51:17, Robert Hyatt wrote: >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... I think you are misreading my statements - and I am _not_ continuing with what was initially posted. <rambling> There is this usual perception that 'deep blue solved chess' - which is a load of shit : and if nothing, this will disprove it. Yes , it might have been strong for programs of its time : thats all. Compared to programs of today , it may get a sound thrashing. Crafty was getting what - 15-17 ply at WCCC2005 ? And deep blue was getting like 12 or so ? </rambling> We cannot really approximate Deep blue since we dont know what was put inside it - what eval , what extension parameters (other than the published ones) , how bad was its branching factor , how bad was its move ordering , how it was doing qsearch , pruning , how stupid was its speedup (not approximate extrapolated values : actual time to depth reduction) etc - and in most of these , naw - all of these , it will be very inferior to what most of us do today - simply because 7 years is a lot of time and much progress has been made. So how best can we approximate it ? I strongly suspect if IBM will ever bring it out of cold storage and allow us to practically test a match ;) The best we can do is : Take a bugfree program like crafty , add SE to it (very very expensive) , remove null move from it , remove egtb , essentally try to dumb it down to what might have been available at deep blue's times (you might be having crafty versions from that time right ?) and give it a 1000x speed advantage. This is _not_ going to be a deep blue versus crafty match - but an approximation vs crafty match. Note : the singular extension shortcuts that Bruce (he did it right ?) posted were an approximation and not close to being as expensive as what deep blue did - and even Bruce's methods tend to be very expensive without nullmove pruning as depths increase (it will not be a static 2 ply advantage). I am not sure how many takers will be there for this 'match' , but it will definitely be an interesting contest. And , you are up really late :) Regards, Mridul
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