Author: John Merlino
Date: 12:23:14 03/03/04
Go up one level in this thread
On March 03, 2004 at 13:48:07, Joachim Rang wrote: >On March 03, 2004 at 13:39:40, John Merlino wrote: > >>On March 03, 2004 at 10:38:23, Joachim Rang wrote: >> >>>On March 03, 2004 at 10:14:50, Uri Blass wrote: >>> >>>>I wonder if the solution f6 is correct solution >>>> >>>>[D]r3r1k1/6p1/1pqp2Np/2p1nP1P/N1PbPQ2/1P3PR1/P2K4/7R w - - 0 1 >>>> >>>>I could not find a convincing line after f6 Nxc4+ but maybe I miss something. >>>> >>>>Movei could not solve it at 5 minutes per position on A1000 becasue after few >>>>minutes it changed its mind from f6 to Nc3 after failing low at depth 10. >>>> >>>>Uri >>> >>>I think you just discovered an error in this testsuite. Most engines fail low >>>over and over after: >>> >>>1.f6+ Nxc4+ 2. bxc4 Qxa4 3. f7+ Kh7 >>> >>>more (engine)-analysis will follow. >>> >>>regards Joachim >> >>I don't think there is a problem. After forcing those moves, Chessmaster 9000 >>(SKR personality on a P4-2.4) still shows a good score for White. I think >>(perhaps inadvertantly) the point is that f6 is the BEST move and that the >>engine shouldn't fail TOO low on f6 Nxc4+...? Not sure.... >> >>Perhaps the point is to see that, after the above moves, White must play 4.Rc1 >>rather than 4.fxe8=Q which leads to a draw. >> >>I also believe, after a lot of analysis and playing around with lines, that f6 >>does not necessarily lead to a forced win. I DO believe that it is the best >>move, however. >> >>Here is what The King says: >> >>Time Depth Score Positions Moves >>27:10 2/14 1.42 387147633 4.Rc1 Qxa2+ 5.Rc2 Qa5+ 6.Ke2 Qa4 >> 7.Rc1 Rf8 8.Nxf8+ Rxf8 9.Rg6 Qa2+ >> 10.Qd2 Qa7 11.Qd3 Qxf7 12.Rb1 Qf4 >> 13.Rxb6 >> >>jm > > >go deeper in the variations. For example after 4.Rc1 Qxa2+ 5.Rc2 Qa5+ 6.Ke2 Qa4 >7.Rc1 Rf8 8.Nxf8+ Rxf8 9.Rg6 >9... Qa7! draws. > >What score does CM9SKR shows after Nc3? My analysis stopped at 9.Rg6, because CM9 has a difficult time determining the best move here. Depending on the time control, it could play Rg6, Qd2 or Kf1. All have evals in the neighborhood of +0.5 for White, but the evals were slowly dropping. Which, as I said, leads me to believe that f6 does NOT necessarily lead to a forced win, but that it is the best move. After 1.Nc3, CM9SKR says Black wins after 1...Nxc4+ 2.bxc4 Bxc3+ 3.Kxc3: Time Depth Score Positions Moves 0:00 1/4 -0.04 9967 1...b5 2.cxb5 Bxc3+ 3.Kxc3 Qxb5 4.Kb2 0:00 1/5 0.42 45754 1...b5 2.cxb5 Bxc3+ 3.Kxc3 Qxb5 4.Nxe5 Qb4+ 5.Kc2 dxe5 0:00 1/6 0.42 148074 1...b5 2.f6 Bxc3+ 3.Kxc3 b4+ 4.Kd2 Rxa2+ 5.Ke3 Qb7 6.fxg7 0:02 1/7 0.78 434070 1...b5 2.f6 Qc7 3.Nxe5 Bxe5 4.Qxe5 dxe5 5.Rxg7+ Qxg7 6.fxg7 bxc4 0:04 1/7 0.69 743221 1...d5 2.cxd5 Qf6 3.Na4 Kh7 4.Nxe5 Bxe5 0:10 1/8 0.00 2007590 1...d5 2.Nxd5 Rxa2+ 3.Kd1 Ra1+ 4.Kc2 Ra2+ 5.Kd1 0:24 1/9 0.07 5005359 1...d5 2.exd5 Qf6 3.Rc1 Bxc3+ 4.Rxc3 Nf7 5.a4 Nd6 6.Re3 Qb2+ 7.Kd1 1:05 1/10 0.00 13307035 1...d5 2.exd5 Qf6 3.Rc1 Nxc4+ 4.bxc4 Bxc3+ 5.Rxc3 Rxa2+ 6.Rc2 Qa1 7.Rxa2 Qxa2+ 8.Kc3 Qa1+ 9.Kd3 Qb1+ 10.Kd2 Qa2+ 3:42 1/11 0.00 46789493 1...d5 2.f6 Bxc3+ 3.Kxc3 d4+ 4.Kc2 Rxa2+ 5.Kd1 Ra1+ 6.Kc2 Ra2+ 4:24 1/11 -0.05 55885892 1...Nxc4+ 2.bxc4 Bxc3+ 3.Kxc3 Qa4 4.Qc1 Qb4+ 5.Kd3 Ra3+ 6.Ke2 Rc3 7.Qd1 Qb2+ 8.Qd2 Rc2 9.Rd1 Rxd2+ 10.Rxd2 10:45 1/12 -1.13 138913431 1...Nxc4+ 2.bxc4 Bxc3+ 3.Kxc3 Qa4 4.Qc1 Qb4+ 5.Kd3 Ra3+ 6.Ke2 Rc3 7.Qe1 Qxc4+ 8.Kf2 Rc2+ 9.Ke3 d5 10.Rg4 dxe4 11.fxe4 Rxa2 18:15 1/13 -1.13 238745890 1...Nxc4+ 2.bxc4 Bxc3+ 3.Kxc3 Qa4 4.Qc1 Qb4+ 5.Kd3 Ra3+ 6.Ke2 Rc3 7.Qe1 Qxc4+ 8.Kf2 Rc2+ 9.Ke3 d5 10.Rg4 dxe4 11.fxe4 Rxa2 So it looks like 1.f6 is definitely best.... jm
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