Author: leonid
Date: 18:22:07 08/16/00
Go up one level in this thread
On August 16, 2000 at 18:41:15, Dann Corbit wrote: >On August 16, 2000 at 18:37:12, leonid wrote: > >>On August 16, 2000 at 16:57:08, Jari Huikari wrote: >> >>>[D]3R1B1K/5p2/2p2p2/b1rPNP1n/q1rkNP2/1Pp2Q2/1n6/5B2 W - - >>>[D]1B1N4/p2n4/3P1P2/2nk1BP1/P7/N7/K3P2P/1Q6 W - - >>>[D]kbb2rr1/1p6/p3p1q1/PN1pB3/1n6/R3Q3/5PB1/6K1 W - - >>> >>>These were quite hard positions for Nero. >>>It needed 143 s. for the first one, 262 for the second and the third >>>wasn't yet solved in 12 minutes. >>> >>> Jari >> >>Thanks for good positions in good graphics! Much easier to see and solve. >> >>You forgot to say what is your computer and your program. >> >>Your first position is mate in 4 moves. Can be solved by selective search 4 >>moves ahead but not by simple one. By selective search (my computer is AMD 400. >>Mate solver in LLchess) position was solved in slightly less that one second. By >>brute force search it took 4 seconds. >> >>Second position. Mate in 3 moves. Could be solved by selective search as well. >>Can't say exactly the time needed to solve it. Too tiny. Both ways (selective >>and brute force) take less that 0.055 of one second. > >This is very interesting, because I have only seen mate in 4. Can you show the >correct pv for mate in 3? Thanks for saying me so! As usual, problem is in wrong position. I put white queen c1 when it must be put on b1. When white queen is on b1 then mate is in 4 moves. White bishop goes from b8 to a7. When white queen is on c1 that position is mate in 3 moves. White queen goes from c1 to c4. When position is original one (4 moves mate) it can be solved by selective and brute force search. In both ways it take 0.65 of one second. Leonid. >>Third position. Mate in 8 moves. Can be solved by selective and brute force >>search. Both ways it take less that 0.055 of one second to solve. >> >>To give you practical idea how long it will take in real program to solve all >>those position, will give you numbers from my program. My program have mate >>solver that work before every new move. It solved first two positions in less >>that 0.055 and missed the last one. It missed the third one because it take only >>as far as 7 moves ahead. >> >>You could be surprised that default mate solver took first position in less that >>0.055 sec. Reason for this is that it looked more moves ahead that this position >>demand as minimum. It solved it in 7 moves ahead. >> >>Leonid.
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.