Author: Ed Schröder
Date: 16:16:41 07/21/00
Go up one level in this thread
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.
>This _was_ deep thought. It was doing about 2M nodes per second in 1995,
>according to Hsu.
Then Hsu is wrong or the IBM site.
Quote from the IBM site:
"Deep Thought acquires 18
additional customized chess
processors and emerges as
Deep Thought II. It now is
running on an IBM/6000 and
can search six to seven million
chess positions per second.
6 to 7 million NPS. This in the year 1991 so 4 years before the Hong Kong
event. So according to Hsu and/or IBM in 1995 the machine dropped from 7 to
2 million NPS?? One might expect the opposite, a faster machine after
4 years but not a slower one. Something ain't right with these numbers.
>Fine. Again, Hsu is a liar. If that is what you want to think. Here is
>an excerpt from him that might help:
>
>===============================================================================
>Web-based DB Jr uses a single card, a random opening book (including
>fairly bad lines) and one second per move (a quarter of which is used
>in downloading the evaluation function, and the search extensions are
>more or less off due to the very short time). It probably plays at around
>2200, which is usually sufficient to play against players in random marketing
>events. Repetition detection is also turned off (The web-based program
>is stateless). The playing strength of "DB Jr." spans a quite wide range,
>depending on the setup. The top level, which we used for analysis and
>in-house training against Grandmasters, is likely in the top 10 of the
>world.
>================================================================================
I said the contradiction is in the private emails so you can't know.
Ed
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