Author: Robert Hyatt
Date: 13:08:20 12/08/99
Go up one level in this thread
On December 08, 1999 at 15:28:46, Eugene Nalimov wrote: >Main benefit from hashing is not cutoff of the entire line - that happens rare >in the middlegame (let's say speedup will be ~10%). Main benefit is that you >often get the best move from the shallow search, and there are good chances that >that move will be good for deeper search. Even slightly better moves ordering >helps alphabeta a lot. > >And of course it's better to have iterative deepening as well. > >Eugene Correct. Here is the mother of all positions to test hashing on, from Fine's "Basic Chess Endings" position number 70: /k/3p/p2P1p/P2P1P///K/ w if hashing works, you will get to 30 plies instantly. If it doesn't, you won't get to 15. > >On December 08, 1999 at 15:10:16, leonid wrote: > >>On December 08, 1999 at 13:25:15, Vincent Diepeveen wrote: >> >>>On December 08, 1999 at 10:45:15, leonid wrote: >>> >>>>On December 08, 1999 at 10:17:47, Robert Hyatt wrote: >>>> >>>>>On December 08, 1999 at 08:32:48, leonid wrote: >>>>> >>>>>>Hello! >>>>>> >>>>>>How many plies chess game should have before hash tables could be of some use in >>>>>>the chess game? >>>>>> >>>>>>Thanks, >>>>>>Leonid. >>>>> >>>>> >>>>>Three + captures should do it: >>>>> >>>>>Nh3 xxx Ng5 >>>>>Nf3 xxx Ng5 >>>>> >>>>>and you avoid the rest of the 2nd search... >>>> >>>>Thanks! >>>> >>>>I tryed up to 5 plys and had no improvement. Something wrong with my logic. Will >>>>go back and try 8 plies deep. >>> >>>there are always bugs in hashings... ...test it well, create at least >>>a functoin that calculates the hashkey in the current position, and >>>compare that with the incremental value. I bet there are some mistakes >>>there! >>> >>>After that check go figure out how you store it. I've had nasty bugs >>>when compressing a lot of info into a few bits. >> >> >>I see that what you said have a good sense. I already killed one bug and rewrote >>my hash logic for plies from 7 to 5. Still no speeding. Probably some bug more. >>It sound so strange, since this part of logic apparently is so simple. Will >>later go down to the minimax and see the difference. Alpha-beta can obscure >>efficency of hashing. >> >>Leonid. >> >> >>> >>>>Leonid.
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