Author: Len Eisner
Date: 19:34:36 12/21/99
Go up one level in this thread
On December 21, 1999 at 19:09:04, blass uri wrote: >On December 21, 1999 at 18:32:11, Len Eisner wrote: > >>On December 21, 1999 at 09:11:08, James T. Walker wrote: >> >>>On December 20, 1999 at 23:46:37, blass uri wrote: >>> >>>>On December 20, 1999 at 21:48:29, Len Eisner wrote: >>>><snipped> >>>>>In any case, the position I mentioned should be covered by the KPP vs KP 5 >piece tablebase which I do have loaded. So I don't know why Fritz 6 (and >H7.32 for that matter) plays f7 since it is obviously not the fastest winning >line. >>>> >>>>f7 is the fastest winning line that fritz6 and hiarcs7.32 know by tablebases >>>>of H732. >>>> >>>>They know nothing about kqp vs kp so the fact that there is a faster winning >>>>line(leading to KQP vs KP) is not relevant >>>> >>>> >>>>Uri >>> >>>Hello Uri, >>>I believe you are right. He should have the KQPKP tablebase to make this >>>endgame work properly. It may even be counter productive to have any "Pawn" >>>tablebases without the proper "Promotion" tablebases to follow up. For the >>>KPPKP tablebase you should have the KQPKP and KPPKQ at the very minimum. These >>>endings are usually easy wins for the side with the Queen but that does not mean >>>that they are not required for the programs to transition into them correctly >>>from the KPPKP ending. >>>Jim Walker >> >> >>Hopefully, the KQPKP and KPPKQ will be included on the Chessbase Endgame Turbo >>CD. The files are too large for me to download. >> >>I still don't understand why KppKp does not know the shortest winning line. Why >>have it if it is not usable without the other tablebases? I assumed it would >>know the best pawn to promote, and after that, the program would be on its own >>unless you had the other tablebases. > >The reason is that the tablebases do not include moves but only distance to mate >information for every position and the engine does not know to promote >the pawn because the distance to mate is not known after promoting the pawn and >is known after other moves. > >it may prefer always mate in 20 by not moving the pawn and not shorter mate by >promoting because the tablebases do not have the number of moves of the shorter >mate. > >The right way to use tablebases(if you have only part of them) is to stop using >them when the distance to mate is decreased but Hiarcs732 and Fritz6 do not know >it(crafty fixed this problem). > >Uri You're right. I tried the position with Crafty 16.18, and it correctly played g8=Q with mate in 8. Again, the position is 8/6P1/5P2/1k6/8/p7/8/6K1 w - - 0 1 Len
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