Author: leonid
Date: 05:32:17 05/05/01
Go up one level in this thread
On May 05, 2001 at 01:48:34, Angrim wrote: >On May 04, 2001 at 16:05:36, leonid wrote: > >>On May 04, 2001 at 15:38:23, Angrim wrote: >> >>>On May 04, 2001 at 10:26:02, leonid wrote: >>> >>>>Hello! >>>> >>>>Had bad lack this midnight when one call came from my work. It took me 20 >>>>minutes to do it but I went to my bed only at 2 o'clock. One good result from >>>>broken sleep was this position that you can try to solve. It probably will >>>>demand one sleepless night from your program, if you will insist on shortest >>>>mate. >>>> >>>>[D]RnqkqnR1/qBNbNBq1/QqQqQqQ1/BrQqQrB1/3q4/8/3Q4/3K4 w- - >>>> >>>>Please indicate your result. >>>> >>>>Thanks, >>>>Leonid. >>> >>>this one IS tough, wonder if having endgame tables would help a lot? >> >>Never! >ok, it just looked like there were some lines where most of the pieces >would get swapped off. > >> >>>I'll leave my proof number searcher running while I'm at work, maybe it >>>will find an answer in a few hours.. currently its obsessing over Qxd7. >> >>Everything depend on each program branching factor. Two professional that I >>tried until now (they are not specialized in solving mate nut never hung on you) >>were slow. The every next program could have very good branching factor for this >>position. I had the chance to see very good on mine, mainly for brute force. >>Selective was slow. It took this in 10 min 42 sec. Celeron 600Mhz. No hash. >> >>Leonid. >> > >program finished shortly after I left for work >proved that move e6xd7 wins, 17 turns >PN2:94098802 evals, 2821179 expands 1258.90 seconds > >I am sure that it did not find the shortest mate, since pn search is >incredibly selective. It searched most lines to 12 ply, but a few went >as deep as 73 ply(these may have traded down to K vs Kb or some such). Your result sound to me as the move that lead to shortest mate anyway. My program found symetrical move from left side, it was C6-D7. I found mate in 13 and since Heiner reached already first 12 moves by brute force, this position is for sure mate in 13. Leonid. >It ended up proving that 44 of the 69 legal moves for white lost. >Angrim
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.