Author: blass uri
Date: 08:23:41 10/13/98
Go up one level in this thread
On October 13, 1998 at 07:34:46, Bernhard Bauer wrote: >On October 13, 1998 at 06:05:55, blass uri wrote: > >> >>On October 13, 1998 at 05:54:00, blass uri wrote: >> >>> >>>On October 13, 1998 at 04:34:00, Amir Ban wrote: >>> >>>>On October 13, 1998 at 02:12:24, Jouni Uski wrote: >>>> >>>>>In SSDF game archive there is 5834 games. In 21 games there is KQ-KR ending. >>>>>And 20 of these were won by Q side WITHOUT any use of TBs! Quite surprising - >>>>>isn't this normally considered as difficult ending? >>>> >>>>I've never seen this ending in a computer-computer game where the side with the >>>>queen failed to win, at any time control. >>>> >>>>This endgame is quite easy for a computer. >>> >>>Is it easy when the defendor use tablebases? >>> >>>I found that the defendor without tablebases(when the defendor is a computer >>>program) may miss a simple draw by perpetual check in positions when there is >>>black queen at f2 and white king at h1. >> >>Here is an example >> >>7R/8/8/8/8/k7/5q2/7K white to move and draw >>Fritz5(without tablebases) plays Rg8 and Junior5(16 bit) Rh3+ >>when Ra8+ is the only way to draw. >> >>Uri >> > >Crafty 15.20 finds the draw without tablebases. >On a 2xPPro 233MHz crafty sees Ra8+ at ply 14 in 2:48 min. >Crafty sees the draw (score =-0.66) at ply 23 in 3:45 min. >The output for ply 42 is: > 42-> 8:04 -0.66 1. Ra8+ Kb3 2. Rb8+ Kc3 3. Rc8+ Kd3 > 4. Rd8+ Ke3 5. Re8+ Kd4 6. Rd8+ Ke4 > 7. Re8+ Kd5 8. Rd8+ Kc4 9. Rc8+ Kb4 > 10. Rb8+ Ka4 11. Ra8+ Kb5 12. Rb8+ > Ka5 13. Ra8+ Kb6 14. Rb8+ Kc5 15. Rc8+ > Kd6 16. Rd8+ Kc6 17. Rc8+ Kd7 18. Rd8+ > Ke6 19. Re8+ Kd5 >Kind regards >Bernhard You need to search at least 54 plies forward to see the stalemate or repetition and many programs cannot search more than 50 plies. I think that most of the top programs cannot search to 42 plies in this position even in 8000 minutes. I think that crafty is more than 1000 times faster than most of the top programs in finding the draw. Uri > > >> >>> >>>Uri >>>> >>>>Amir
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.