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Subject: Re: Dead Wrong!

Author: Ed Schröder

Date: 00:33:52 07/22/00

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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


>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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