Author: Uri Blass
Date: 03:14:03 08/27/02
Go up one level in this thread
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." 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. 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? 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)? 4)Did they do test games to prove that the sacrifice of 2 plies was productive (I can understand if they assumed it without testing because they had not enough time to test)?. 5)They give average number of nodes of 126M nodes per second. Is it the number of nodes(not only effective nodes) that they searched? 6)They give estimate of efficiency of 8-12% I am not sure about the meaning of it. What is the estimate for the number of nodes per second that they needed to get the same depthes with the same evaluation and extension rules but no parallel search? Uri
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