Author: Bernhard Bauer
Date: 23:29:11 02/24/99
Go up one level in this thread
On February 24, 1999 at 09:28:15, Bernhard Bauer wrote: I forgot to mention that J. Awerbach says that the position is a draw if black is to move. Usually Awerbach's analysis is very good, but here he may be wrong. Crafty gives a score of -Mat45, so there may be no way to draw. The new compressed tablebases give at least for me new possibilities in analysis of end game positions. It would be nice if tbstat would also work for compressed files. Kind regards Bernhard >Hallo, >I came across a position from W. Chenkin,1960 in a book of J. Averbach. >Here is the position: > > +---+---+---+---+---+---+---+---+ > 8 | | | | | | | | | > +---+---+---+---+---+---+---+---+ > 7 | | | | | | | | | > +---+---+---+---+---+---+---+---+ > 6 | | | | | | | | | > +---+---+---+---+---+---+---+---+ > 5 | | | | | | | | | > +---+---+---+---+---+---+---+---+ > 4 | | | | | | | | | > +---+---+---+---+---+---+---+---+ > 3 | | | | | | | Q | | > +---+---+---+---+---+---+---+---+ > 2 | K | *P| | | | *R| | | > +---+---+---+---+---+---+---+---+ > 1 | | | | | | *K| | | > +---+---+---+---+---+---+---+---+ > a b c d e f g h > >FEN: 8/8/8/8/8/6Q/Kp3r/5k > >For white to move Crafty gives: >White(1): end-game phase > clearing hash tables > time surplus 0.00 time limit 10:00 (10:00) > depth time score variation (1) > 1 0.13 1.80 1. Qe3 > 1-> 0.14 1.80 1. Qe3 > 2 0.14 1.78 1. Qe3 Re2 > 2 0.24 ++ 1. Qd3+!! > 2 0.24 Mat51 1. Qd3+ Kg2 2. Qe4+ <EGTB> > 2-> 0.25 Mat51 1. Qd3+ Kg2 2. Qe4+ <EGTB> > 3 0.25 Mat51 1. Qd3+ Kg2 2. Qe4+ <EGTB> > 3-> 0.28 Mat51 1. Qd3+ Kg2 2. Qe4+ <EGTB> > 4 0.32 Mat51 1. Qd3+ Kg2 2. Qe4+ <EGTB> > 4-> 0.41 Mat51 1. Qd3+ Kg2 2. Qe4+ <EGTB> > time=0.86 cpu=32% mat=3 n=643 fh=85% nps=747 > ext-> checks=101 recaps=0 pawns=0 1rep=4 > predicted=0 nodes=643 evals=72 > endgame tablebase-> probes done=135 successful=131 plimit=6 > hashing-> trans/ref=33% pawn=99% used=0% > SMP-> split=0 stop=0 data=0/64 cpu=0.28 elap=0.86 > >mate in 51 moves. > >This may be not enough to win due to the 50 moves rule. >When I do a search for the move that J. Awerbach gives in his book, Qg4! >Crafty gives some different output: > >White(1): White(1): end-game phase > clearing hash tables > time surplus 0.00 time limit 10:00 (10:00) > depth time score variation (1) > 1 0.11 1.70 1. Qg4 > 1-> 0.11 1.70 1. Qg4 > 2 0.11 1.68 1. Qg4 Rd2 > 2-> 0.11 1.68 1. Qg4 Rd2 > 3 0.21 ++ 1. Qg4!! > 3 0.24 Mat41 1. Qg4 Rd2 2. Qf4+ <EGTB> > 3-> 0.24 Mat41 1. Qg4 Rd2 2. Qf4+ <EGTB> > 4 0.24 Mat41 1. Qg4 Rd2 2. Qf4+ <EGTB> > 4-> 0.24 Mat41 1. Qg4 Rd2 2. Qf4+ <EGTB> > time=0.69 cpu=20% mat=3 n=275 fh=82% nps=398 > ext-> checks=69 recaps=0 pawns=0 1rep=0 > predicted=0 nodes=275 evals=69 > endgame tablebase-> probes done=62 successful=62 plimit=7 > hashing-> trans/ref=32% pawn=99% used=0% > SMP-> split=0 stop=0 data=0/64 cpu=0.14 elap=0.69 > >mate in 41 moves. > >This would suffice for a win. >So may question is simply weather Crafty could be improved in that area. > >Kind regards >Bernhard
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.