Author: Robert Hyatt
Date: 10:48:26 10/14/02
Go up one level in this thread
On October 14, 2002 at 07:34:16, Bas Hamstra wrote: >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. > I read it, and I posted the relevant part. He said "12 plies is brute-force part of search". 6 plies is hardware partition. there could be up to 6 more plies beyond the 12 ply PV. Seems pretty clear to me, too, and not in the way you are thinking, apparently. Just don't over look the _second_ part of that answer about the "up to 6 additional plies"... > > >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
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