Author: Robert Hyatt
Date: 14:06:32 09/09/01
Go up one level in this thread
On September 09, 2001 at 15:09:44, Vincent Diepeveen wrote: >On September 09, 2001 at 09:51:42, Robert Hyatt wrote: > >>On September 09, 2001 at 08:39:13, Vincent Diepeveen wrote: >> >>>On September 08, 2001 at 23:18:09, Robert Hyatt wrote: >>> >>>>On September 08, 2001 at 14:02:41, Vincent Diepeveen wrote: >>>> >>>>>On September 08, 2001 at 13:53:03, K. Burcham wrote: >>>>> >>>>>Yes it had to, because it was a preprocessor program, >>>>>perhaps it didn't clear 'best move' entries in the software. >>>> >>>> >>>>This is not a given. You can be a pre-processor without clearing the hash >>>>between _every_ pair of moves. You only need to clear the hash scores if you >>>>change some of the evaluation weights. Nothing says a pre-processor has to >>>>do this after each move. Early versions of crafty did some pre-processing, but >>>>only at two distinct places in the game, namely on the transition between >>>>opening to middlegame and middlegame to endgame. That resulted in _exactly_ >>>>two hash table clear operations in a game. I see no reason why your assumption >>>>has to be valid at all. >>> >>>the important thing is that it didn't use hashtables at all in >>>hardware and that it of course couldn't use transposition entries from >>>a previous search. Obvoiusly you don't need to clea rit, but practically >>>it comes down to the same thing. >> >> >>Why? If the root positions for move #X and move #X+1 are similar, then no >>evaluation weights need to be changed. And the hash table _and_ scores can >>be re-used just fine. This is what I did in early versions of Crafty. > >right but that is very primitive chess code. If they would do the >same their evaluation would be even more primitive and they completely >unnecessary would load each time new PSQ values to the processors. I think that is a ridiculous statement to make. _your_ program is a form of pre-processor. It loads the piece/square tables _one_ time at the beginning of the game. Just like I do. Is that even more primitive than a program that adjusts them 3 times during a game? Which is more primitive than a program that adjusts them after _every_ move in a game? I don't follow this reasoning at all... > >> >> >>> >>>If you can't use search scores from a previous search, then in human >>>eyes it is completely justified to say that this sucks bigtime! >> >> >> >>But there is nothing to say they couldn't. Crafty used to be a pre-processor >>for lots of things, and it knew when to clear the hash and when it didn't need >>to, with a simple check in the preprocessor phase. > >> >> >>> >>>> >>>> >>>>> >>>>>Note that it didn't use hashtables onboard of each hardware >>>>>cpu either. >>>>> >>>>>> >>>>>> >>>>>> >>>>>> >>>>>>i assume deep blue had some type of memory storage for eval >>>>>> of previous lines searched. if it did are you saying that >>>>>> deep blue cleared its memory (hash), with each move? >>>>>> >>>>>>if it did not clear its memory with each move then your seven >>>>>> second search limit does not make sense to me. >>>>> >>>>>>and can you tell me which game this move was taken from, so that i >>>>>> can get a better analysis of this position. i can find it, but you >>>>>> can save me a lot of time, if you will. >>>>>> >>>>>>i will post my results after the analysis of this position. >>>>>> >>>>>>kburcham
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