Author: Ed Schröder
Date: 02:53:14 07/22/00
Go up one level in this thread
On July 22, 2000 at 05:35:12, Dave Gomboc wrote: >On July 22, 2000 at 03:33:52, Ed Schröder wrote: > >>On July 21, 2000 at 23:00:49, blass uri wrote: >> >>>On July 21, 2000 at 22:27:45, Robert Hyatt wrote: >>> >>>>On July 21, 2000 at 19:16:41, Ed Schröder wrote: >>>> >>>>>On July 21, 2000 at 15:29:26, Robert Hyatt wrote: >>>>> >>>>>If you don't mind I only answer those points not earlier discussed >>>>>(enough) to avoid ending up in endless circles. >>>>> >>>>> >>>>>>>2) DB is no brute force program (as you always have claimed). Quote >>>>>>>from the IBM site: >>>>>>> >>>>>>> "Instead of attempting to conduct an exhaustive "brute force" >>>>>>> search into every possible position, Deep Blue selectively >>>>>>> chooses distinct paths to follow, eliminating irrelevant searches >>>>>>> in the process." >>>>>>> >>>>>>>I always said this after I had seen the log-files. It beats me how you >>>>>>>always have claimed the opposite on such a crucial matter presenting >>>>>>>yourself as the spokesman of Hsu even saying things on behalf of Hsu >>>>>>>and now being wrong on this crucial matter? >>>>>> >>>>>>Sorry, but you are wrong and are interpreting that wrong. DB uses _no_ >>>>>>forward pruning of any kind, this _direct_ from the DB team. The above is >>>>>>referring to their search _extensions_ that probe many lines way more deeply >>>>>>than others. If you want to call extensions a form of selective search, that >>>>>>is ok. It doesn't meet the definition used in AI literature of course, where >>>>>>it means taking a list of moves and discarding some without searching them at >>>>>>all. >>>>> >>>>>The quoted text describes DB as a selective program, no brute force. I >>>>>don't see how you can explain it otherwise. The text is crystal clear. >>>>> >>>>> >>>> >>>>Why don't you simplyh ask Hsu, or are you afraid you will get an answer >>>>you don't want? DB was _always_ brute force. Every document written about >>>>DB said this. The paragraph you are quoting is talking about "selective >>>>search extensions" which was one of the real innovations from the Deep Thought >>>>development (singular extensions, later used by Lang, Kittinger, Moreland, >>>>Hyatt, who knows who else). >>>> >>>>You _know_ they were basically in the same mold as the rest of us. This has >>>>_never_ been in doubt. >>>> >>>>If you do doubt it, just ask the horse's mouth, since you don't want to believe >>>>me. >>> >>>I do not believe to things that seem illogical. >>> >>>I do not want to believe the 17-19 brute force depth with no pruning of deep >>>blue because it sounds too good to be right. >> >>You are right Uri. Doing 17-19 brute force in the middle game is IMPOSSIBLE. >> >>Ed > >Some time ago I referred to a paper authored by Hsu, Campbell, and >Hoane(published in 1999) that described it being full-width at the top of the >software search, selective near the tips of the software search, and full-width >again at the top of the hardware search. > >I recall that previous DT/DB stuff was full-width the whole way, but this >apparently was changed for DB2 -- i.e. I think Bob's info re: "search is >entirely full-width" is not correct for the second match vs. GK. > >I don't have a copy of the paper anymore, but I did fax Ernst Heinz a copy >shortly after it came out, so he might have it around still. > >Dave This all makes much more sense to me. The brute force method is an out-dated principle throwing away many elo points for no good reason. Ed
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