Author: Dan Homan
Date: 07:06:27 07/22/00
Go up one level in this thread
On July 22, 2000 at 05:44:36, Ed Schröder 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 remember reading this (or a similar statement) on their website back during the second Kasparov match. I never got the impression that this was a statement from the programmers of Deep Blue to their peers. Rather, I got the impression this was a statement from a web page designer to the general public who know nothing about "alpha-beta" and would consider a brute force search a look at every possible position. "Brute force" is even defined this way in the statement. The statement simply says that Deep Blue eliminates irrelevant searches... this could be nothing more than the "alpha-beta" algorithm. Those webpages are likely maintained by a large number of individuals - none of whom are likely to have worked on the Deep Blue project. The information there has been filtered for a general audience. To draw conclusions from that information is probably a mistake. Sometimes you will be right and sometimes you will be wrong, but you won't know which is which. Drawing conclusions from this information, just because it is "all that is available" does not make the conclusions any more right. What this boils down to is the Deep Blue is no longer available. It hasn't really been available to the computer chess community since the last tournament in 1995. In 1995 and earlier, there was no doubt that Deep Thought and its successors where the best and the best by a large margin. Did they lose the tournament in 1995 to a micro? Yes, but so what. The laws of probability say they had to lose sometime. It is simply a must. The strongest player will not always win a short swiss tournament. The very fact that they did win so many short swiss tournaments shows by how large a margin they were leading the field. Even in the 1995 tournament where they placed second to Fritz, it looks like they lost due to a single move... maybe it was a bug, maybe it was connection trouble, but to use this move to infer that this means they were tactically weak is silly - very silly considering their other performances. (Oh, and counting a match played against a web interface of something claiming to be Deep Blue doesn't count as evidence as we have no idea - other than speculation and conflicting private communications - what it was and how strong it was. Again, the statement "it is the only information we have" doesn't make it any more right.... In science, we know that it is always better to have no data than bad data.) Deep Blue is not the best around, because they are no longer around. Would they be the best around if they were still around (and had advanced in the last three years like everybody else)? I don't know. My guess is that they would be the best and by a large margin, but it only a guess. Some people are speculating that they would not be the best. Maybe they are right. - Dan >>>>>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). > >I disagree. Extensions are always selective. Some moves are extended >some don't and that makes that extensions is a selective process by nature. >So the text (about brute force) can't be related to the previous sentence >(about extensions). They made 2 statements (not one). > > >>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. >> >> >> >>> >>>>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. >> >> >>That was correct. But as I said (after a conversation with Hsu) it _never_ >>really ran at that speed. The few times they tried to use all the hardware, >>things didn't work out very well (this was mainly used during the Fredkin >>stage II matches, where they physically shipped the machine (a single Sun >>workstation + the VME cards) to remote locations. >> >>Hsu has said point blank, the most recent version of DT was searching about >>2M nodes per second. I take him at his word, since he built the thing... > >The only thing that counts here is the contradicting data: > >1991: IBM 7 million >1995: Hsu 2 million > >Now who to believe that's the question. > > > >>> >>>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. >> >> >>Simply email Hsu... it was his box. He can tell you what you want to >>know... >> >> >>> >>> >>>>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 >> >> >>No, but I believe from the above, which is also private email, there is >>absolutely no confusion in what "web DB Jr" was. It is _very_ clear, and >>not open to misinterpretation, wouldn't you say?? >> >>It was thrown together at the request of marketing guys. And "thrown together" >>is a pretty accurate description. He says "2200". In another email he said >>"2200 might have been optimistic"... > >Every time it is something else. I stopped believing it. > >Ed
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