Author: Robert Hyatt
Date: 12:07:31 07/02/02
Go up one level in this thread
On July 01, 2002 at 17:34:00, Alessandro Damiani 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? >> >>Their evaluation function is quite complete but far from impressive (nothing >>that a good micro program doesn't do - at least nothing important). >> >>The job they have done on search is on the other hand poor in my opinion. >> >>Poor is an understatement. Given the money they have been given for the project, >>the almost total lack of work on the search algorithms is a shame. >> >>If they knew as much as many amateur programmers nowadays, they would have >>worked harder on the search. It is obvious that more work on this would have >>given much, much better results. >> >>The problem is that they have started their project with the level of knowledge >>about search algorithms that was up to date at the time of Chess 4.8. >> >>They have invested almost no work on search before starting to design the chips. >>And since they have not invested much time on this either when they were working >>on revisions of the chips, in the end they have got chips able to do the kind of >>search that was great... back in the seventies. >> >>Their chips do a brute force search, with a few exotic (most probably >>inefficient) extensions. >> >>Since nearly twenty years we know that brute search is vastly inferior to a good >>selective search. >> >>They have done a great achievement with a technique that is known to be vastly >>inferior. >> >>That leaves a bitter taste of what could have been achieved with the same >>resources if they only had somebody capable enough (read: averagely skilled by >>CCC's standards) on the subject of chess tree searching in their team. >> I _still_ have a problem reading that last paragraph. I wonder if Christophe knows exactly who Murray Campbell is? IE he wrote the _first_ difinitive paper on null-move search. He conned me into being the _first_ person to implement what is now known as "PVS search" (null-window) at the 1978 ACM event (more on this if you want to hear an interesting story). Singular extensions. a 2200+ chess player. I can't imagine _anybody_ saying "if they only had someone capable enough, averagely skilled by CCC standards, etc" if they actually _know_ Murray... Murray is anything _but_ "averagely skilled by CCC standards..." Anything but... And then there is Hsu, Hoane, Thomas, Andrew, etc... >> >> >> Christophe, writing this under... Linux!!! :-) > >Which Linux distribution do you use? Thx. > >Alessandro
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