Author: Robert Hyatt
Date: 16:22:42 07/03/03
Go up one level in this thread
On July 03, 2003 at 18:40:50, Uri Blass wrote: >On July 03, 2003 at 18:22:14, Robert Hyatt wrote: > >>On July 02, 2003 at 16:46:57, Uri Blass wrote: >> >>>On July 02, 2003 at 12:47:00, Russell Reagan wrote: >>> >>>>On July 02, 2003 at 08:33:36, Michel Langeveld wrote: >>>> >>>>>Does a (bugfree) program need 26 ply, 18 ply, or different to see that this >>>>>position is > 2. (normal plies, no pawn, singulair extensions). >>>>> >>>>>I think a normal ply searcher needs more as 18 ply to see in all variations that >>>>>the f5 or b6 goes off the board. >>>>> >>>>>How much ply does your program need? >>>>> >>>>>[D]8/k7/3p4/p2P1p2/P2P1P2/8/8/K7 w - - >>>> >>>>I believe you need 26 ply without a hash table, and 18 ply with a correctly >>>>working hash table. This position is usually used to test whether or not your >>>>hash table is working correctly. >>> >>>I believe that you cannot say how much plies a program needs without knowing the >>>extension and pruning rules that it is using. >>> >>>Uri >> >>I don't think he meant 26 plies of search depth. He meant 26 plies of >>moves. There aren't going to be any extensions in this position until a >>pawn gets captured, which means a depth of 26 plies is needed without some >>serendipitous help from hashing. > >I think that it depends on the program. >Crafty does not use extensions until a pawn gets captured and the same is for >movei of today but it does not mean that it is the case for all programs. > >Uri Of course, but I can't see anything that might possibly trigger an extension in fine 70. No checks. No captures. No pawn moves. just king shuffling until the black king has to make a choice and let the white king penetrate. You _might_ extend there but by then it is solved anyway.
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