Author: martin fierz
Date: 06:39:00 06/21/01
Go up one level in this thread
On June 21, 2001 at 09:28:32, Uri Blass wrote: >On June 21, 2001 at 05:56:46, martin fierz wrote: > >>On June 20, 2001 at 14:25:03, John Hatcher wrote: >> >>>Maybe the answer to my question is obvious, but I'd be interested in what >>>programmers have to say on the subject. >>> >>>I've recently been running matches between Fritz6 and Chess Tiger. On my old >>>Celeron 333mhz computer Fritz6 runs at about 250 knps, and Chess Tiger runs at >>>about 80-100 knps. To my delight, and surprise, Chess Tiger is doing very well >>>against Fritz - very well. >>> >>>Since, as I understand it, "nps" is related (at least nominally) to search depth >>>in a given time period, it would seem that, all things being equal, the greater >>>the "nps" the stronger the program. >>> >>>Of course, things are never really equal between two programs. As evidence of >>>that, Chess Tiger with its lower nps holds its own quite nicely against Fritz. >>>For this to happen it would seem that Chess Tiger must have some chess >>>"knowledge" programmed into it that allows it go toe-to-toe with a program that >>>searches 2.5x as many positions per second. >>> >>>Is the programming of this chess knowledge, even among the programmers of top >>>commercial programs, still as much art as science so that the programmer of >>>Chess Tiger has found a "smarter", more efficient way to implement chess >>>knowledge into Chess Tiger. I guess I supposed that much of this knowledge >>>would be common currency by now. >>> >>>Sorry for the long-winded question. I wanted to be clear. >>> >>>JOHN >> >>in my checkers program, i have various move ordering schemes. if i turn them on, >>i get much less nodes/seconds, but i can search deeper all the same. the >>same goes for ETC - using it lowers nodes/sec, but has a net positive effect. >>i can choose to run my program at 1.1MN/sec without these things or at 750kN/sec >>with them, and it's better in the 'slow' mode. >>there may also be a big difference in the eval. i know fritz does something fast >>but stupid: before starting the search, it assigns pieces values depending on >>which square they are. these values remain unchanged during the search (AFAIK). >>the result is a fast search but a dumb evaluation - i'm sure they tested it and >>found it to be ok, but it can be very irritating at times. > >I am sure they testeed it and found it not o.k and this is the reason that Deep >Fritz or Fritz6a almost do not do it. > > > it is of course >>well-known that if you have a king which is not too safe, you should try to >>exchange queens. fritz eval understands this, and gives the attacking side a >>bonus - BUT: in the lookahead, it keeps this in, even if the queens are traded. >>it will evaluate a line with a queen trade as +1 for the side with the safe >>king, but once the queen is gone, it will suddenly say 'equal' - which is >>correct, but it didnt see it in the lookahead. i find this very disconcerting >>when analyzing games with fritz... > >It seems that you have an old Fritz version. >I do not see it with my Deep Fritz. > >Uri that's great! i only have the fritz 5.32 that comes with chessbase 8 and if find it a nuisance when analysing games that it does this. i didnt know that the newer fritzes stopped doing it. cheers martin
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