Author: Miguel A. Ballicora
Date: 16:27:08 01/04/02
Go up one level in this thread
On January 04, 2002 at 19:15:52, Uri Blass wrote: >On January 04, 2002 at 18:58:34, Uri Blass wrote: > >>On January 04, 2002 at 17:35:01, Gian-Carlo Pascutto wrote: >> >>>Bleh! Sjeng sees that Nxb5 loses in a few seconds, but it does >>>not find any better move! >>> >>>The score for Nxb5 is now -1.2 or so and Sjeng does not >>>fail high on the other moves, so it would still play it >>>after more than 10 minutes thought. >> >>After Nxb5 Rf5 the advantage of black >>is clearly bigger than +1.2 >> >>+1.2 is not a winning advantage and after Nxb5 tiger saw +4 >> >>I believe that one of >>Ne4 or g3(the move that tiger expected) or Re1 >>are better(I am not sure if they save the game but they should be better from >>computer point of view) >> >>Everything seems to avoid Nxb5 after enough time and I expect sjeng to play a >>different move if you give it enough time. >> >> >>Here is yace's opinion >> >>after 1.g3 >> >>New position >>8/5rbk/6q1/1p1Q4/1PpP2p1/2N2pP1/5P2/3R2K1 b - - 0 1 >> >>Analysis by Yace 0.99.56: >> >>1...Rf5 2.Qe4 >> ³ (-0.46) Depth: 3 00:00:00 >>1...Rf5 2.Qd7 Qh5 >> ³ (-0.61) Depth: 3 00:00:00 >>1...Rf5 2.Qd7 Qh5 >> ³ (-0.61) Depth: 3 00:00:00 >>1...Rf5 2.Qd7 Qh5 >> ³ (-0.61) Depth: 3 00:00:00 >>1...Rf5 2.Qd7 Qh5 3.Re1 >> ³ (-0.49) Depth: 4 00:00:00 >>1...Rf5 2.Qd7 Qh5 3.Re1 Rg5 >> ³ (-0.46) Depth: 5 00:00:00 3kN >>1...Qf5 2.Qxb5 Qxb5 3.d5 Qxd5 4.Rxd5 >> ³ (-0.47) Depth: 5 00:00:00 5kN >>1...Qf5 2.Qxb5 Qxb5 3.Nxb5 Rb7 4.Nc3 >> ³ (-0.61) Depth: 5 00:00:00 5kN >>1...Qf5 2.Qxb5 Qxb5 3.Nxb5 Rb7 4.Nc3 Rxb4 >> ³ (-0.61) Depth: 6 00:00:00 14kN >>1...Qf5 2.Qxb5 Qxb5 3.Nxb5 Rb7 4.Nc3 Rxb4 5.Kf1 >> ³ (-0.56) Depth: 7 00:00:00 35kN >>1...Qf5 2.Qxb5 Qxb5 3.Nxb5 Rb7 4.Nd6 Rxb4 5.Nf5 c3 6.Nxg7 >> ³ (-0.65) Depth: 8 00:00:00 154kN >>1...Qf5 2.Qxb5 Qxb5 3.Nxb5 Rb7 4.Nd6 Rxb4 5.Nf5 Bf6 6.d5 c3 >> ³ (-0.67) Depth: 10 00:00:02 1183kN >>1...Rf5 2.Qb7 Rh5 3.Nxb5 Qh6 4.Qe4+ Kg8 5.Qxg4 Rxb5 6.Qc8+ Kh7 7.d5 Qg5 8.Qxc4 >> ³ (-0.68) Depth: 10 00:00:04 1603kN >>1...Rf5 2.Qb7 Rh5 3.Ra1 Qh6 4.Qe4+ Kh8 5.Ra8+ Bf8 6.Rxf8+ Qxf8 7.Qxg4 Qf7 8.Kf1 >> µ (-0.93) Depth: 10 00:00:05 2014kN >>1...Rf5 2.Qe4 Rh5 3.Re1 Qxe4 4.Rxe4 Bf8 5.Re5 Rxe5 6.dxe5 Bxb4 7.Nxb5 c3 >> µ (-0.99) Depth: 11 00:00:08 3639kN >>1...Rf5 2.Qe4 Rh5 3.Re1 Qxe4 4.Rxe4 Bf8 5.Re5 Kg6 6.Rxb5 Rxb5 7.Nxb5 Bxb4 >> µ (-0.97) Depth: 12 00:00:14 5789kN >>1...Rf5 2.Qe4 Rh5 3.Re1 Qxe4 4.Rxe4 Bf8 5.Re5 Kg6 6.Rc5 Bxc5 7.dxc5 Kf5 8.Nxb5 >>Ke5 >> µ (-0.91) Depth: 13 00:00:28 11708kN >>1...Rf5 2.Qe4 Rh5 3.Re1 Qxe4 4.Rxe4 Bf8 5.Rxg4 Bxb4 6.Ne4 Kh6 7.Rf4 Rd5 8.Rxf3 >>Rxd4 9.Rf6+ Kg7 >> µ (-1.02) Depth: 14 00:01:10 28264kN >> >>(Blass, Tel-aviv 05.01.2002) >> >>After Nb5 Rf5 yace fails low again and again and >>I did not give it enough time to finish depth 12 >> >>New position >>[D]8/6bk/6q1/1N1Q1r2/1PpP2p1/5p2/5PP1/3R2K1 w - - 0 1 >> >>Analysis by Yace 0.99.56: >> >>2.Qxf5 Qxf5 >> -+ (-4.40) Depth: 1 00:00:00 >>2.Qxc4 >> +- (1.80) Depth: 1 00:00:00 >>2.Qxc4 Rh5 >> +- (1.49) Depth: 2 00:00:00 >>2.Qxc4 Rh5 3.Kf1 >> +- (1.70) Depth: 3 00:00:00 >>2.Qxc4 Qb6 3.Nc3 Rh5 >> +- (1.48) Depth: 4 00:00:00 >>2.Qxc4 g3 3.gxf3 Rxf3 4.fxg3 Rxg3+ 5.Kf1 >> +- (1.50) Depth: 5 00:00:00 17kN >>2.Qxc4 g3 3.gxf3 Rxf3 4.Rb1 Qxb1+ 5.Kg2 >> ± (1.10) Depth: 6 00:00:00 31kN >>2.Qxc4 g3 3.gxf3 Rxf3 4.Qc1 Rxf2 5.Kh1 >> ² (0.28) Depth: 6 00:00:00 31kN >>2.Qd7 Rxb5 3.Qxb5 fxg2 >> ² (0.29) Depth: 6 00:00:00 31kN >>2.Qd7 Rh5 3.Qc8 Rxb5 4.gxf3 >> ² (0.28) Depth: 6 00:00:00 31kN >>2.Qxc4 g3 3.gxf3 Rxf3 4.Qc1 Rxf2 5.Kh1 >> ² (0.28) Depth: 6 00:00:00 31kN >>2.Qxc4 g3 3.gxf3 Rxf3 4.Kf1 Rxf2+ 5.Kg1 Qf5 6.Rc1 >> = (0.19) Depth: 7 00:00:00 312kN >>2.Qxc4 Qh5 3.Qc2 g3 4.gxf3 gxf2+ 5.Qxf2 Rxb5 6.Qc2+ Kg8 >> = (-0.17) Depth: 8 00:00:03 1074kN >>2.Qxc4 Qh5 3.Qc2 g3 4.gxf3 gxf2+ 5.Qxf2 Rxb5 6.Kf1 Qh3+ 7.Qg2 Qxg2+ 8.Kxg2 Kg6 >>9.d5 >> ³ (-0.32) Depth: 9 00:00:07 2273kN >>2.Qxc4 Qh5 3.Qc2 g3 4.gxf3 gxf2+ 5.Qxf2 Rg5+ 6.Kf1 Qh3+ 7.Qg2 Rxg2 8.Ke1 >> µ (-0.72) Depth: 10 00:00:11 4155kN >>2.Qxc4 g3 3.gxf3 Rxf3 4.Kg2 Qe4 5.Kg1 gxf2+ 6.Kf1 Qc2 7.Qxc2+ Kg8 >> -+ (-1.43) Depth: 10 00:00:32 11453kN >>2.Qxc4 g3 3.gxf3 Qh5 4.fxg3 Qxf3 5.Qc2 Qxg3+ 6.Kh1 Qg6 7.Qh2+ Rh5 8.Na3 Rxh2+ >>9.Kxh2 >> -+ (-1.83) Depth: 11 00:00:49 17447kN >>2.Qxc4 Qh5 3.g3 Qh3 4.Qf1 Qxf1+ 5.Kxf1 Rh5 6.Kg1 Rxb5 7.d5 Rxb4 8.d6 Rd4 9.Rxd4 >> -+ (-2.61) Depth: 11 00:01:17 26933kN >>2.Qxc4 g3 3.gxf3 Qh5 4.fxg3 Qxf3 5.Qc2 Qxg3+ 6.Kh1 Qf3+ 7.Kg1 Kg8 8.Nd6 Qg3+ >>9.Qg2 Qe3+ 10.Kh2 Rh5+ 11.Qh3 Rxh3+ 12.Kg2 >> -+ (-3.01) Depth: 12 00:03:17 68881kN >>2.Qxc4 g3 3.gxf3 Rxf3 4.Kg2 Qe4 5.Kg1 gxf2+ 6.Kf1 Qg6 7.Qd3 Rxd3 8.Kxf2 >> -+ (-4.01) Depth: 12 00:03:57 81979kN >>2.Qxc4 g3 3.fxg3 f2+ 4.Kf1 Qh5 5.Qd3 Qh1+ 6.Ke2 f1Q+ 7.Rxf1 Qxf1+ 8.Kd2 Qxd3+ >>9.Kxd3 Rxb5 10.Kc4 Rg5 11.d5 Rxg3 >> -+ (-5.02) Depth: 12 00:05:27 112849kN >> >>(Blass, Tel-aviv 05.01.2002) >> >> >>Uri > >after finishing depth 12 here is yace's line > >2.Qe4 Rxb5 3.Qe1 Bf8 4.d5 Rxb4 5.Qe6 c3 6.Qd7+ Kg8 7.Qc6 Qc2 8.Qe6+ Kg7 > -+ (-4.02) Depth: 12 00:17:44 381827kN But this does not tell the whole story. It is obvious that after Qe4 White is lost, but the real reason (for a human point of view) is hidden because the computer avoids it. The idea is that After Qxc4 or any other move that defends the kight, g3 is crushing (gxf3 Qh6/ fxg3 Qe3+ this e3 square is important see below). That is why some computers want to play 1.g3 others 1.Ne4 and some others Re1 because that defend the square e3. Interesting position. Regards, Miguel > >(Blass, Tel-aviv 05.01.2002) > >yace agrees that Nxb5 is losing more than 4 pawns >when other moves do not lose so much. > >g3 was only one example and yace believes that >black advantage is less than 1 pawn after a move like Ne4 >that seems better than g3 to me(only 0.61 pawns >after some minutes) > >Uri
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