Author: Robert Hyatt
Date: 20:31:57 08/27/02
Go up one level in this thread
On August 27, 2002 at 20:36:30, Dave Gomboc wrote: >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 Actually, based on this recent paper, the DB2 chip apparently had SE added when it was re-designed... I was not aware of it specifically, but then I had not asked either since the original deep thought stuff did not do SE in the hardware. whether or not it did the double-SE and whatever is not clear at all from the paper, however... just that the software was doing that was all that was clearly stated.
This page took 0 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.