Author: Dave Gomboc
Date: 17:36:30 08/27/02
Go up one level in this thread
On August 27, 2002 at 06:14:03, Uri Blass wrote: >On August 27, 2002 at 04:34:16, Dave Gomboc wrote: > >>On August 25, 2002 at 23:39:29, Robert Hyatt wrote: >> >>>On August 25, 2002 at 21:56:03, Dave Gomboc wrote: >>> >>>>On August 22, 2002 at 16:09:07, Uri Blass wrote: >>>> >>>>>On August 22, 2002 at 15:51:28, Jeremiah Penery wrote: >>>>> >>>>>>On August 22, 2002 at 06:47:34, Gian-Carlo Pascutto wrote: >>>>>> >>>>>>>That does not make sense - it only does when you take the first number as >>>>>>>the nominal ply depth and the second number as the part of that that was >>>>>>>done by the hardware searches. >>>>>> >>>>>> >>>>>>So what does it mean when you have searches like this, >>>>>> >>>>>>--> 17. Be3 <-- 23/113:12 >>>>>>--------------------------------------- >>>>>>Guessing Qc7 >>>>>> 3(4) 25 T=0 >>>>>>qd1d2 Pc5c4 pb3c4P >>>>>> 4(5) 25 T=0 >>>>>>qd1d2 Pc5c4 pb3c4P >>>>>> 5(5)[Qd2](25) 25 T=1 >>>>>>qd1d2 Pc5c4 pb3c4P >>>>>> 6(5)[Qd2](25) 25 T=2 >>>>>>qd1d2 Pc5c4 pb3c4P Qc7c4p >>>>>> 7(5) #[Qd2](28)##################################### 28 T=4 >>>>>>qd1d2 Re8b8 nf3e5P Pd6e5n >>>>>> 8(6) #[Qd2](28)##################################### 28 T=12 >>>>>>qd1d2 Re8b8 bc2d3 Pa6a5 pc3c4 >>>>>> 9(6)<ch> 'ng6' >>>>>>--------------------------------------- >>>>>>--> Ne7g6 <-- >>>>>>--------------------------------------- >>>>>> 28 T=19 >>>>>>qd1d2 >>>>>> 3(4)[Qd2](30) 30^ T=1 >>>>>>qd1d2 Pc5c4 pb3c4P Pb5c4p >>>>>> 3(5) 35 T=1 >>>>>>qd1d2 Qd8c7 pb3b4 Pc5c4 be3h6P >>>>>> 4(5) 35 T=1 >>>>>>qd1d2 Pa6a5 pa2a3 >>>>>> >>>>>> >>>>>>where you have depths like 3(4)? They can't have 3 nominal plies, where 4 of >>>>>>those plies come from the hardware, because obviously that's impossible. >>>>> >>>>>A good question. >>>>> >>>>>I do not understand the meaning of the second mnumber >>>>>but the first number is clearly the brute force depth based on their paper. >>>>> >>>>>Maybe the second number is about some limit about the extensions but OI do not >>>>>know. >>>>> >>>>>Uri >>>> >>>>Uh, is that what you guys are all discussing _again_? >>>> >>>>Sheesh. >>>> >>>>The first number is the depth of the software search. The second number is the >>>>depth of the hardware search. I posted this _years_ ago after asking a member >>>>of the DB team directly: check the archives. >>>> >>>>Dave >>> >>>That is what I was told also. However, a fairly new paper really clouds the >>>issue in that they mix depths between DB2 in the 1997 match, DB Jr on slower >>>hardware, etc... >>> >>>I think that the only explanation for the (x) number is the one given by the >>>team to me. And apparently to you as well, and probably others that simply >>>don't post here... >> >>Often when they refer to their search tree they refer to the software depth >>only. Which paper is causing the kerfuffle? >> >>Dave > >A paper by Murray Campbell,Joseph Hoane Jr and Feng-hsiung Hsu (august 1 2001) > >In that paper they said the following in page 5: > >"A three minute search on deep blue would reach a full width depth of 12.2 on >average." > >"The estimate is based on a linear least squares fit on all the iteration,log >time data points from the 1997 match against kasparov." I suppose you could take the information from the logs, compute this, and see if 12.2 is the average software search depth or the average total (software + hardware) search depth. >They also say in page 13 the following about deep blue Jr: >"For a given iteration i,the software is assigned i-4 ply which represent the >minimum depth search in software." > >They never said that iteration means different things in deep blue Jr and deep >blue so it is logical to assume that if iteration is software+hardware in deep >blue junior it is also the case in deep blue. All the same, I think what they just meant was that in Deep Blue Jr., the hardware was set to search four ply, independent of the (software) search depth. I don't believe they're using "iteration" here to mean exactly the same thing as when they used "full width depth" in the other quote above. >I have some questions for them that I did not understand from the paper: >I will be happy if they answer only by yes/no when they can answer the last >question by a number. > >1)Does iteration mean the minimal depth that they could not miss tactics(In >other words in the worst case they could miss tactical line of 13 plies when >they searched iteration 12)? > >2)Does iteration mean the software search in deep blue II? From the one quote, it sounds like iteration means software + hardware. But in another context they may use iteration differently? >3)Did they use only selective search in the hardware(they say in comment 3 in >page 5 that their experiment showed that deep blue sacrificed 2 plies >of full width searrch in order to execute the selective search algorithm)? Their software search includes selectivity (extensions!). ASAICR, the hardware chips can't do singular/dual/etc. extensions. Dave
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