Author: Vincent Diepeveen
Date: 12:09:44 09/09/01
Go up one level in this thread
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. > > >> >>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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