Author: Dann Corbit
Date: 20:44:10 05/21/04
Go up one level in this thread
On May 21, 2004 at 22:12:00, Uri Blass wrote: >On May 21, 2004 at 20:30:53, Dann Corbit wrote: > >>On May 21, 2004 at 20:25:04, Uri Blass wrote: >> >>>On May 21, 2004 at 20:17:21, Mike Byrne wrote: >>> >>>>On May 21, 2004 at 19:32:33, George Tsavdaris wrote: >>>> >>>>>Black threatens mate and white's Queen. What white should play? >>>>>Give it's Queen of course! Qf4!! and white is winning. >>>>> >>>>> Impressive for humans but not for computers, as any chess engine can solve >>>>>this in seconds.... >>>>> >>>>>[D]1kbr3r/pp6/8/P1n2ppq/2N3n1/R3Q1P1/3B1P2/2R2BK1 w - - 0 1 >>>> >>>> >>>>Black(1): mt 2 >>>>max threads set to 2 >>>>Black(1): 1kbr3r/pp6/8/P1n2ppq/2N3n1/R3Q1P1/3B1P2/2R2BK1 w - - 0 1 >>>>White(1): go >>>> clearing hash tables >>>> time surplus 29.92 time limit 1666:39 (1666:39) >>>> depth time score variation (1) >>>>starting thread 1 >>>> 1 0.00 2.84 1. Qxc5 >>>> 1-> 0.00 2.84 1. Qxc5 >>>> 2 0.00 -1 1. Qxc5 >>>> 2 0.00 -Mat01 1. Qxc5 Qh1# >>>> 2 0.00 -9.26 1. Qe5+ Nxe5 2. Nxe5 Rxd2 3. Rxc5 >>>> 2 0.02 -8.25 1. Bg2 Nxe3 2. Rxe3 >>>> 2-> 0.02 -8.25 1. Bg2 Nxe3 2. Rxe3 >>>> 3 0.02 -8.25 1. Bg2 Nxe3 2. Rxe3 >>>> 3-> 0.04 -8.25 1. Bg2 Nxe3 2. Rxe3 >>>> 4 0.04 -8.62 1. Bg2 Nxe3 2. Rxe3 Qh2+ 3. Kf1 Nd3 >>>> 4-> 0.05 -8.62 1. Bg2 Nxe3 2. Rxe3 Qh2+ 3. Kf1 Nd3 >>>> 5 0.07 -8.58 1. Bg2 Nxe3 2. Rxe3 Nd3 3. Rc2 >>>> 5 0.07 -8.29 1. Qf4+ gxf4 2. Bxf4+ Ka8 3. Nb6+ axb6 >>>> 4. axb6+ Na6 5. Rxc8+ Rxc8 6. Rxa6+ >>>> bxa6 7. Bg2+ Rc6 8. Bxc6# >>>> 5-> 0.08 -8.29 1. Qf4+ gxf4 2. Bxf4+ Ka8 3. Nb6+ axb6 >>>> 4. axb6+ Na6 5. Rxc8+ Rxc8 6. Rxa6+ >>>> bxa6 7. Bg2+ Rc6 8. Bxc6# (s=9) >>> >>> >>>What is this? >>>Crafty evaluates mate as -8.29 pawns? >>> >>>Movei always evaluates mate as Mate-ply when ply is the number of plies from the >>>root position. >> >>Crafty has not resolved the mate yet. Crafty is sure of a win (at +8 pawns, it >>is almost impossible to lose). But a 5 ply search with 8 hundredths of a second >>has not determined for a certainty that there is no alternative to checkmate. >> >>It is also possible to see a pv with a # in it that is not a checkmate at all. >>So that knife cuts both ways. > >no >8.29 at depth 5 is for black when the mate is for white. You are right. It took 1/2 second at ply 8 to see the mate in 11: 8 0.54 Mat11 1. Qf4+ gxf4 2. Bxf4+ Ne5 3. Bxe5+ Rd6 4. Bxd6+ Ka8 5. Nb6+ axb6 6. axb6+ Na6 7. Rxc8+ Rxc8 8. Rxa6+ bxa6 9. Bg2+ Qf3 10. Bxf3+ Rc6 11. Bxc6#
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.