Author: Bas Hamstra
Date: 04:34:16 10/14/02
Go up one level in this thread
Bob, did you read the Hsu transcript posted here? It is pretty clear to me that Hsu himself says 12 ply fullwidth *total*. Case closed. Please read the complete transcript. Best regards, Bas. On October 13, 2002 at 21:27:08, Robert Hyatt wrote: >On October 13, 2002 at 15:35:12, Vincent Diepeveen wrote: > >>On October 13, 2002 at 14:40:12, James Swafford wrote: >> >>I wonder why. there is just one person ever in this whole >>planet who said 12(6) = 18 ply, and that's robert hyatt. > > >First, _I_ didn't say that. The deep blue team _specifically_ said that and I >posted the >relevant part of an email showing that. So you can, at _any_ time you choose, >finally >decide to make an accurate statement (not much chance of that happening, of >course) >and perhaps say "they told bob something that was wrong." > >I don't know that what they said was wrong, because if you read Hsu's answer >today, >"12 plies, plus up to _another_ 6" seems to follow the explanation given in the >email >sent to me... > >Second, it is apparent that you have made up your mind here, just as you make it >up >in other circumstances, and then _nothing_ is going to change your mind after >that. >It is impossible. It can't be done. I can "proof" that it can't be done >because I tried >it in Diep and it didn't work..." And so forth. > >All utter nonsense. > > >> >>there is 4 the same statements from hsu. >> a) page 5 at his paper. >> b) 3 in this talk >> >>there is many statements from hyatt in 98 and 99 that it was >>getting 12 ply, when in 99 at world champs many got 12 ply it was >>18 ply suddenly... >> >>But the clearest statement is next: >> >>EeEk(* DM) kibitzes: kib question from ardee: Does "12(6)" mean 12 total ply or >>12+6=18 total ply? This has the been source of huge arguments for years! >> >>directly the answer came a few seconds later: >> >>CrazyBird(DM) kibitzes: 12 total in terms of brute force. 6 is just the max >>partition in hardware. > >Why stop there. There is _another_ sentence that is important... > >"up to 6 more moves ..." > >Aha. You stop where you want so that you can "proof" something once >again??? > > >> >> >> >> >>>On October 13, 2002 at 14:25:00, Vincent Diepeveen wrote: >>> >>>>On October 13, 2002 at 12:00:39, Andrew Williams wrote: >>>> >>>>It was answerred another 2 times that it's 12 ply simply, >>>>excluding qsearch+extensions. So the hardware is inside that >>>>12 ply, but the hardware depth FROM that 12 ply can be UP to >>>>6 ply. So it isn't always searching 6 ply in hardware. It's >>>>a variable depth which they can do in hardware. That explains >>>>probably extensions around mainlines with captures very well >>>>and do not forget that the chips could do up to 1 billion nodes >>>>a second in theory. >>> >>>Ok, if you say that was answered, I believe you, but that >>>doesn't sound like what the quote I responded to in a thread below >>>meant. Can you provide the transcript for this? Seriously, >>>I would very much like to see it. >>> >>> >>> >>>> >>>>It searched on average over a period of 3 minutes only 126 MLN >>>>nodes from that. that's only 10% effective usage or so each >>>>chip. That means that there are *always* loads of chips idling. >>>> >>>>So getting extra processors to the PV is a very clever thing to >>>>do then. Of course you give the chips a small search depth then. >>>>2 to 3 ply is what Brutus was using at world champs 2002. Bigger >>>>search depths in hardware were too inefficient. >>>> >>>>You cannot use killermoves in hardware and you cannot use hashtables >>>>and Hsu didn't use nullmove either. With his last so many plies pruning >>>>(whatever name you want to give it, razoring, futility pruning) that means >>>>that when searching the Principal variation, you have to give many processors >>>>small search depths, because the pruning around principal variation is >>>>a lot less than for the other moves. >>>> >>>>It would be interesting to hear in a next chat how many plies the forward >>>>pruning was in the hardware part. Here just doing 1 or 2 ply didn't >>>>reduce anything. Yet i remember some statement from a talk at M$ from >>>>Hsu recently where (was it Tom kerrigan) asked Hsu about forward pruning >>>>in the hardware chips and he answerred he was doing that. >>>> >>>>So what type of pruning he did there is not so interesting. Interesting is >>>>that it saved them up to 90% nodes in hardware. That's very clever, because >>>>chrilly concluded that without forward pruning in hardware, your tree gets >>>>just TOO huge (because move ordering is near random). >>>> >>>>Chrilly uses nullmove. If Deep Blue used something else there. Only >>>>interesting thing from my viewpoint therefore is to know how many plies >>>>they did this forward pruning in hardware. >>>> >>>>My own experiments are not relevant here too much, because i use hashtable >>>>and nullmove everywhere. So it is very well possible that without nullmove >>>>the effect of forward pruning is way bigger than without. >>>> >>>>>Several people asked: >>>>> >>>>>Question: What does "12(6)" mean in Deep Blue's logs? >>>>> >>>>>Dr Hsu said, "12(6) means 12 plies of brute force (not counting the search >>>>>extensions & quiescence). 6 means the maximum hardware search depth allowed. >>>>>this means that the PV could be up to 6 plies deeper before quiescence." >>>>> >>>>>Unfortunately questions were being fed through a third-party, so it wasn't >>>>>possible to get a follow-up. >>>>> >>>>>Andrew
This page took 0.05 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.