Author: Robert Hyatt
Date: 11:54:06 10/19/01
Go up one level in this thread
On October 18, 2001 at 14:44:35, Rafael Andrist wrote: >On October 18, 2001 at 14:27:06, Robert Hyatt wrote: > >>On October 18, 2001 at 14:23:44, Rafael Andrist wrote: >> >>>On October 18, 2001 at 14:20:39, Dann Corbit wrote: >>> >>>>On October 18, 2001 at 10:47:50, Rafael Andrist wrote: >>>> >>>>>On October 18, 2001 at 08:51:56, Robert Hyatt wrote: >>>>> >>>>>>On October 17, 2001 at 17:49:39, Robert Hyatt wrote: >>>>>> >>>>>>>On October 17, 2001 at 13:05:35, Roy Eassa wrote: >>>>>>> >>>>>>>>On October 17, 2001 at 13:02:34, Robert Hyatt wrote: >>>>>>>> >>>>>>>>>On October 17, 2001 at 11:15:12, Robert Hyatt wrote: >>>>>>>>> >>>>>>>>>>definitely a bug of some sort... >>>>>>>>> >>>>>>>>>A pretty simple bug in fact. I just fixed it in the 18.12 source and >>>>>>>>>re-copied the source to the ftp machine. If you want to try the fix, >>>>>>>>>feel free. There was a bad calculation that failed when the king was within >>>>>>>>>one square of the rook-file promotion square, and the pawn was within one square >>>>>>>>>of the promotion square, and the pawn was to move first... >>>>>>>> >>>>>>>> >>>>>>>>Was the bug only in 18.12, or was it also in previous versions? >>>>>>> >>>>>>> >>>>>>>Been there a while... Nothing has been changed here for several versions. I >>>>>>>am completely rewriting the EvaluateDraws() code and have changed the name to >>>>>>>EvaluateWinner(). It returns a bitmask of two bits, 01 means white can win >>>>>>>only, 10 means black can win only, 11 means either can win, and 00 means dead >>>>>>>drawn. >>>>>>> >>>>>>>It also recognizes a few more cases. I temporarily deleted the 18.12 source >>>>>>>as I want to fix this completely as part of the final 18.12 release. I hope to >>>>>>>finish it tonight... >>>>>> >>>>>> >>>>>>New version is now available. It at least handles the test position for this >>>>>>thread correctly. The search is more "stable" in the endgame as well, now. >>>>> >>>>>Did you include this KBP-KP case or did you only fix the bug in the evaluation >>>>>of KBP-K endgames? Do you also handle cases, where the defending king is near >>>>>enough, but can be forced to go away? E.g. >>>>> >>>>>[D]5k2/8/3K3P/8/8/8/2B5/8 w - - 0 1 >>>> >>>>EPD Kit revision date: 1996.04.21 >>>>unable to open book file [e:\crafty\release/books.bin]. >>>>hash table memory = 192M bytes. >>>>pawn hash table memory = 80M bytes. >>>>EGTB cache memory = 32M bytes. >>>>draw score set to 0.00 pawns. >>>>choose from book moves randomly (using weights.) >>>>choose from 5 best moves. >>>>book learning enabled >>>>result learning enabled >>>>position learning enabled >>>>threshold set to 9 pawns. >>>>5 piece tablebase files found >>>>19045kb of RAM used for TB indices and decompression tables >>>> >>>>Crafty v18.12 >>>> >>>>White(1): st 60 >>>>search time set to 60.00. >>>>White(1): setboard 5k2/8/3K3P/8/8/8/2B5/8 w - - >>>>1. Bb3 Ke8 2. h7 Kd8 3. h8=Q# >>>>White(1): >>> >>>What do you want to say? It's clear that it is very easy using EGTB. >>> >>>Rafael B. Andrist >> >>No egtb's >> >> >> 2 0.00 0.00 1. Ke6 Kg8 >> 2 0.00 ++ 1. Bb3!! >> 2 0.00 12.04 1. Bb3 Ke8 >> 2-> 0.00 12.04 1. Bb3 Ke8 >> 3 0.00 ++ 1. Bb3!! >> 3 0.00 13.05 1. Bb3 Ke8 2. h7 Kd8 3. h8=Q# >> 3-> 0.00 13.05 1. Bb3 Ke8 2. h7 Kd8 3. h8=Q# >> 4 0.00 ++ 1. Bb3!! >> 4 0.00 Mat03 1. Bb3 Ke8 2. h7 Kd8 3. h8=Q# >> 4-> 0.01 Mat03 1. Bb3 Ke8 2. h7 Kd8 3. h8=Q# >> 5 0.01 Mat03 1. Bb3 Ke8 2. h7 Kd8 3. h8=Q# >> 5-> 0.04 Mat03 1. Bb3 Ke8 2. h7 Kd8 3. h8=Q# > >Thanks, nearly the same as I get. I was interested if you recoginze it >statically as won. As I can see you don't, therefor it is not very dramatically >if I don't do it too. :-) > >Rafael B. Andrist It is doable, but I didn't want to make it _that_ slow. IE can the king _really_ reach the promotion square first, which means that it would be necessary to check several squares for a path. That sounded like a tree search so I let the tree search do it. :)
This page took 0 seconds to execute
Last modified: Thu, 15 Apr 21 08:11:13 -0700
Current Computer Chess Club Forums at Talkchess. This site by Sean Mintz.