Author: Robert Hyatt
Date: 06:02:34 07/02/02
Go up one level in this thread
On July 01, 2002 at 20:26:44, Christophe Theron wrote: >On July 01, 2002 at 12:21:09, Keith Evans wrote: > >>On June 30, 2002 at 23:59:59, Christophe Theron wrote: >> >>>On June 30, 2002 at 12:28:32, Robert Hyatt wrote: >>> >>>>On June 29, 2002 at 14:18:53, Christophe Theron wrote: >>>> >>>>>On June 28, 2002 at 17:54:56, Keith Evans wrote: >>>>> >>>>>>On June 28, 2002 at 16:33:10, Scott Gasch wrote: >>>>>> >>>>>>>Another idea that I read from was that generating non-capturing checks in the >>>>>>>qsearch against a side that has had a chance to stand pat already is a waste. I >>>>>>>really don't understand this idea and disagree with it. Imagine black has had >>>>>>>an oppertunity to stand pat but instead plays RxN (N appears hung). Well this >>>>>>>looks really good unless white then generates Qd4+ forking blacks R and K and >>>>>>>winning the R. If you neglect to generate checks on a side who has already had >>>>>>>the chance to stand pat you let him get away with RxN and like it. If the only >>>>>>>reason to add checks to the qsearch is to find mates then I agree -- checking >>>>>>>after a side could stand pat is wasted. But if the goal is to improve tactical >>>>>>>play then I think this idea is not sound. >>>>>> >>>>>>I'll be very interested to see what responses this generates. Hsu took the time >>>>>>to design and implement special logic to help generate checking and check >>>>>>evasion moves in Deep Blue which I assume was used in qsearch. This was not a >>>>>>trivial undertaking - it adds both additional logic and additional interconnect. >>>>>>He probably had a good reason for doing it, since he could have used that time >>>>>>for something else like implementing a small hash table. >>>>> >>>>> >>>>> >>>>>And maybe he had no good reason to do it. >>>>> >>>>>As far as I know there are many amateur programmers here that have spent much >>>>>more time in trying and validating ideas (not even speaking of the commercial >>>>>programmers) than Hsu. >>>>> >>>>>I think Hsu and his team have done a great job in implementing a chess program >>>>>in a chip. >>>>> >>>>>However I think taking him and his team as a reference in chess programming is a >>>>>big mistake. >>>>> >>>>>As I have said, I think there are many chess programmers here who are much more >>>>>skilled than Hsu and his team in chess programming. >>>>> >>>>> >>>>> >>>>> Christophe >>>>> >>>>> >>>> >>>> >>>>Hmmm.. I would _never_ make that statement. Have you _ever_ talked with >>>>Hsu or Campbell? I suspect not because if you had, you would not think >>>>them quite that incapable. >>> >>> >>>I did not say that they are incapable. They have done things I will never be >>>able to do. >>> >>>However I have read their description of the Deep genealogy (the document >>>published last year and describing their creatures in details, in particular >>>their evaluation function and search algorithms). >>> >>>I think it's probably as good as or even better than having a talk with them, or >>>else what is the purpose of their publication? >> >>I assume that you're referring to an unpublished version of the paper "Deep >>Blue" Artificial Intelligence 134 (2002) 57-83 (available from >>www.elsevier.com/locate/artint) > > > >Yes. > > > > > >>Do you have any opinion regarding the part related to checks in the qsearch?: >> >>"The main parameters of the hardware search are described below: >>... >>5. Number of ?mating? checks allowed for each side in the quiescence search. >>A mating check is a checking move which allows zero escape squares for the king >>or any checking move which is a ?contact? [15] check by the queen. This >>parameter is used to control the size of the quiescence search. >>6. Number of singular checking moves allowed in the quiescence search (king has >>one escape square, or queen or rook contact check, or any check given while the >>checked side has a hung 16 piece). This parameter is used to control the size of >>the quiescence search. >>... >> >>[15] A contact check is a checking move to a square immediately adjacent to the >>opposing king." > > > >Yes I have an opinion. > >This paragraph as well as many other things I have read in their document shows >that they had some ideas, but due to lack of time to develop and try them, they >end up with something only half baked. So it turns out to be not working and/or >just a waste of time. > >The paragraph above can be interpreted in different ways, but all of them end up >uncovering an inefficiency somewhere: > >1) (most probable) do they call any contact of a queen with the opponent king a >"mating check"? Even in the case where the king or any other piece can simply >recapture the queen? If yes, generating them is in average a waste of time >everywhere in the QSearch and the optimal number of mating checks for this case >is 0. > >2) a contact of the queen and king is defined as a mating check only if the king >has no escape and the queen cannot be captured. In this case it is a checkmate >and if you can detect this in hardware there is no point in generating them. >Just return +MATE and you are done. The optimal number of QSearch moves (plies) >to apply this detection is +INFINITE (apply it everywhere in the QSearch). > >When I read what has been put in the chips (and most of the time has not been >used), I can easily see that they had no idea about what would work and what >would not. > >Any skilled chess programmer would have quickly known. That's what the job is >all about: generate ideas, test them, start again. > >If they had invited a real chess programmer in the team, the last version of the >chips would have been much more efficient. > >What this means is that Hsu and his team were at a very high, professional level >when it is about hardware design. They were at a very amateurish level on the >matter of chess search algorithms. > > > > Christophe What a review. Have you _read_ anything they wrote? "amateurish level on the matter of chess search algorithms"? From the people that wrote _more_ about current search ideas than anybody else? Null-move. Singular extensions. Lots of other extensions. You only have to read what they have written to get a totally different view of what they are capable of.
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