Author: Dan Ellwein
Date: 13:14:40 03/03/04
Go up one level in this thread
On March 03, 2004 at 15:52:57, Uri Blass wrote: >On March 03, 2004 at 15:23:14, John Merlino wrote: > >>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 > >You are right that Nc3 is bad and it seems to be a good test position. > >Note that movei expected Nxc4+ but did not evaluate it correctly. > >yes 9 17430 +215 3458470 f5f6 a8a7 f6g7 a7g7 g6e5 d6e5 g3g7 g8g7 > f4g4 g7h8 g4g6 e8e6 >yes 10 169630 +95 33621526 f5f6 e5c4 b3c4 c6a4 f6f7 g8h7 h1c1 a4a2 > c1c2 a2a5 d2d1 a5a1 c2c1 a1a4 d1e2 a4a2 > f4d2 a2d2 e2d2 a8a2 d2d3 a2a3 d3d2 >no 10 196160 +96 39194072 a4c3 >no 10 216640 +117 43402717 a4c3 e5c4 b3c4 d4c3 d2c3 c6a4 f4c1 a4b4 > c3d3 a8a3 d3e2 a3c3 c1b1 b4c4 e2f2 c3c2 > f2e3 c4e2 e3f4 e2d2 f4g4 d2g5 g4h3 g5h5 >no 10 238400 +117 47912417 a4c3 e5c4 b3c4 d4c3 d2c3 c6a4 f4c1 a4b4 > c3d3 a8a3 d3e2 a3c3 c1b1 b4c4 e2f2 c3c2 > f2e3 c4e2 e3f4 e2d2 f4g4 d2g5 g4h3 g5h5 >no 11 281000 +91 56887247 a4c3 e5c4 b3c4 d4c3 d2c3 c6a4 f4c1 a4b4 > c3d3 a8a3 d3e2 a3c3 c1b1 b4c4 e2f2 c3c2 > f2e3 c4e2 e3f4 e2d2 f4g4 d2g5 g4h3 g5h5 > g6h4 > >Result: Failure > >It seems that movei missed the quiet move d5 in the following line > >[Event "?"] >[Site "?"] >[Date "????.??.??"] >[Round "?"] >[White "New game"] >[Black "?"] >[Result "*"] >[SetUp "1"] >[FEN "r3r1k1/6p1/1pqp2Np/2p1nP1P/N1PbPQ2/1P3PR1/P2K4/7R w - - 0 1"] >[PlyCount "18"] > >1. Nc3 Nxc4+ 2. bxc4 Bxc3+ 3. Kxc3 Qa4 4. Qc1 Qb4+ 5. Kd3 Ra3+ 6. Ke2 Rc3 7. >Qb1 Qxc4+ 8. Kf2 Rc2+ 9. Ke3 d5 * after 30 minutes on a Celeron 1.7G CMOffSet comes up with this... at first 1. ...Nxc4 seems to be the best reply to 1. f6... but on the 12th ply... OffSet thinks that 1. ...Qc7 is the best reply to 1. f6... Time Depth Score Positions Moves 0:00 1/3 2.07 4087 1.f6 Rxa4 2.bxa4 Nxc4+ 3.Kd3 Nb2+ 4.Kc2 Bxf6 0:00 1/4 3.01 16756 1.f6 Qb7 2.Ne7+ Kf8 3.Rxg7 0:01 1/5 3.55 91566 1.f6 Qb7 2.Ne7+ Rxe7 3.fxe7 Qxe7 4.Ke2 Nxc4 5.Qxh6 0:01 1/6 3.60 178868 1.f6 Qb7 2.Ne7+ Rxe7 3.fxe7 Qxe7 4.Qxh6 Nxf3+ 5.Kd3 Bf2 0:05 1/7 3.49 627636 1.f6 Ra7 2.Ne7+ Raxe7 3.fxe7 Nxc4+ 4.bxc4 Qxa4 5.a3 Qxc4 6.Qxh6 0:25 1/8 2.90 2927793 1.f6 Nxc4+ 2.Kd3 Nb2+ 3.Nxb2 Bxf6 4.Kc2 Qb5 5.Kb1 Qe2 6.Qc1 1:52 1/9 2.81 13733268 1.f6 Ra7 2.fxg7 Nf7 3.Nc3 Bxg7 4.Kc2 Qa8 5.a4 4:01 1/10 2.86 31300393 1.f6 Nxc4+ 2.bxc4 Qxa4 3.f7+ Kh7 4.Rc1 Qxa2+ 5.Rc2 Qa5+ 6.Ke2 Qa4 7.Qd2 Red8 8.f8=Q Rxf8 9.Nxf8+ Rxf8 7:28 1/11 2.86 60165933 1.f6 Nxc4+ 2.bxc4 Qxa4 3.f7+ Kh7 4.Rc1 Qxa2+ 5.Rc2 Qa5+ 6.Ke2 Qa4 7.Qd2 Red8 8.f8=Q Rxf8 9.Nxf8+ Rxf8 29:59 1/12 3.62 255545059 1.f6 Qc7 2.fxg7 Nf7 3.Qf5 Bxg7 4.Nf4 Ng5 5.Nd5 Qa7 6.Kc2 Kh8 7.Nac3
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