Author: Alessandro Damiani
Date: 14:34:00 07/01/02
Go up one level in this thread
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. > > > > Christophe, writing this under... Linux!!! :-) Which Linux distribution do you use? Thx. Alessandro
This page took 0.03 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.