Author: blass uri
Date: 20:00:49 07/21/00
Go up one level in this thread
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. I hope programmers will check how many nodes they need to get the same brute force depthes of deeper blue with perfect order of moves(evaluation 0.00 for all positions). I am not sure if it is possible to get the same depth as deep blue in all the cases(assuming perfect order of moves) and if you remember that the order of moves is not perfect(otherwise you do not need to search) and that Deeper blue used extensions then even if it is possible to search their depth with 1/2 of their nodes then it is illogical. Uri
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