Author: Robert Hyatt
Date: 06:51:42 09/09/01
Go up one level in this thread
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. > >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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