Author: Uri Blass
Date: 15:52:25 11/15/05
Go up one level in this thread
On November 15, 2005 at 18:08:13, Uri Blass wrote: >On November 15, 2005 at 17:36:37, Dieter Buerssner wrote: > >>On November 15, 2005 at 07:55:38, Bernhard Bauer wrote: >> >>>On November 14, 2005 at 11:25:28, Vincent Lejeune wrote: >>> >>>>[d]6k1/1p1r1pp1/3p3p/NP1Pp1n1/P3P2n/8/5K1P/4RB2 w - - 0 34 >>>> >>>>Nxb7! >>>> >>>>[Event "?"] >>>>[Site "?"] >>>>[Date "2005.11.06"] >>>>[Round "3.8"] >>>>[White "x"] >>>>[Black "y"] >>>>[Result "*"] >>>>[SetUp "1"] >>>>[FEN "6k1/1p1r1pp1/3p3p/NP1Pp1n1/P3P2n/8/5K1P/4RB2 w - - 0 34"] >>>>[PlyCount "13"] >>>> >>>>34. Nxb7 Rxb7 35. a5 Rc7 36. b6 Rc2+ 37. Re2 Nxe4+ 38. Kg1 Nf3+ 39. Kh1 Rc1 40. >>>>Rxe4 * >>> >>>Thank you for posting this position. >>>For a human it is easy to see that the white a and b pawns are strong. So I >>>changed the PastPawn parameter in Gambitfruit from 100 to 150. >>>Nxb7 is found in 8 sec, however the engine switches to Nc6, which may be a good >>>move too. Changing the the PastPawn parameter to a greater value will result in >>>finding Nxb7 very early and give a good score too. >> >>I suspect, that Gambitfruit changed in this manner will not be able to win this >>position (with not too much time against good defence). >> >>A couple of years ago, I made a similar change to Yace for one test position, >>where an outside passed pawn would win the game. Yace had no problem to find the >>correct move, and create that passed pawn. But it behaved very emberrassing. To >>win, that passed pawn had to be given up later. But because of the high bonus, >>Yace wanted to keep it ... >> >>>[D]8/pR4pk/1b6/2p5/N1p5/8/PP1r2PP/6K1/ b >> >>I had tested this position rather often (the position was also discussed here >>now and then). Some years ago, it seemed very difficult. I guess, with modern >>hardware, many engines will solve it convincingly in short time. >> >>Regards, >>Dieter > > >I think that this position is one of the hardest positions in the ECMGCP > >Here is analysis by latest private Movei > >16 13 65795 315616405 b6d8 h2h3 d8f6 g1f1 f6d4 g2g4 d2f2 f1e1 a7a5 b7a7 f2h2 >a7a5 h2h3 e1e2 h7g6 a5a7 g6g5 >16 14 75787 365947266 d2b2 >16 43 79537 384327836 d2b2 >16 220 282518 1292496939 d2b2 a4b2 c4c3 b7b6 c5c4 b6b4 a7a5 b4b5 c3c2 b5h5 h7g6 >h5d5 c2c1q b2d1 c4c3 d5d8 g6f5 d8d7 >16 220 284237 1301029280 d2b2 a4b2 c4c3 b7b6 c5c4 b6b4 a7a5 b4b5 c3c2 b5h5 h7g6 >h5d5 c2c1q b2d1 c4c3 d5d8 g6f5 d8d7 >17 234 318017 1441306426 d2b2 a4b2 c4c3 b7b6 c5c4 b6b4 a7a5 b4b5 c3c2 b5h5 h7g6 >h5d5 c2c1q b2d1 c4c3 d5d6 g6f7 g2g4 c1f4 d6d7 f7f6 Note that Shredder9 find it very fast and the reason that programs in the past had problem like movei is mainly software problem 6 seconds on A3000 is clearly equivalent to less than 1 minute even on hardware of 2000. Glaurung suprised me by finding Rxb2 in less than 1 second at depth 6 but it lost it only to find it later in a short time(depth 15 with a high score). New game, 8/pR4pk/1b6/2p5/N1p5/8/PP1r2PP/6K1 b - - 0 1 Analysis by Shredder 9 UCI: 1...c3 2.bxc3 Rxa2 3.Nxb6 axb6 4.Rxb6 Ra3 5.c4 Rc3 6.Kf2 Rxc4 7.Rc6 Rc2+ 8.Ke3 Rxg2 9.Rxc5 Kg6 10.h4 Rh2 = (-0.12) Depth: 17/30 00:00:03 1602kN 1...c3 2.bxc3 Rxa2 3.Nxb6 axb6 4.Rxb6 Ra3 5.Kf2 Rxc3 6.h4 c4 7.Rc6 Rc2+ 8.Ke3 Rxg2 9.Rxc4 Kg6 10.Kf4 Rf2+ 11.Kg4 Kf6 = (-0.06) Depth: 18/34 00:00:04 2865kN 1...Rxb2 = (-0.07) Depth: 18/34 00:00:06 4454kN 1...Rxb2 ³ (-0.42) Depth: 18/34 00:00:06 4637kN 1...Rxb2 2.Nc3 Rc2 3.Ne4 c3 4.Kf1 Rc1+ 5.Ke2 c2 6.Kd2 Re1 7.Ng5+ Kg6 8.Kxc2 -+ (-3.66) Depth: 18/40 00:01:01 39616kN 1...Rxb2 2.Nc3 Rc2 3.Ne4 c3 4.Kf1 Rc1+ 5.Ke2 c2 6.Kd2 Re1 7.Ng5+ Kg6 8.Kxc2 Kxg5 9.Rxg7+ Kh6 10.Rg8 Re2+ 11.Kb3 a5 -+ (-3.47) Depth: 19/40 00:01:07 43041kN 1...Rxb2 2.Nc3 Rc2 3.Ne4 c3 4.Kf1 Rc1+ 5.Ke2 c2 6.Kd2 Re1 7.Ng5+ Kg6 8.Kxc2 Kxg5 9.Rxg7+ Kh6 10.Rg8 Re2+ 11.Kb3 Bc7 12.h3 -+ (-3.70) Depth: 20/42 00:01:19 50762kN 1...Rxb2 2.Nc3 -+ (-3.95) Depth: 21/42 00:01:36 62680kN 1...Rxb2 2.Re7 Rxa2 3.Nc3 Ra3 4.Nd5 c3 5.Re2 c4+ 6.Kf1 Ra1+ 7.Re1 Ra2 8.Rc1 Rf2+ 9.Ke1 Rxg2 10.Rxc3 Ba5 11.Kf1 Bxc3 12.Kxg2 Be5 -+ (-4.26) Depth: 21/42 00:02:10 85903kN 1...Rxb2 2.Re7 Rxa2 3.Nc3 Ra3 4.Nd5 c3 5.Re2 c4+ 6.Kf1 Ra1+ 7.Re1 Ra2 8.Rc1 Rf2+ 9.Ke1 Rxg2 10.Rxc3 Ba5 11.Kf1 Bxc3 12.Kxg2 Bd2 13.Kf3 -+ (-4.03) Depth: 22/44 00:02:42 106942kN 1...Rxb2 2.Re7 -+ (-4.28) Depth: 23/46 00:03:16 130900kN 1...Rxb2 2.Re7 Rxa2 3.Nc3 Ra3 4.Nd5 c3 5.Re2 c4+ 6.Kf1 Ra1+ 7.Re1 Ra2 8.Nxb6 -+ (-4.28) Depth: 23/46 00:03:40 146634kN (, 16.11.2005) New game, 8/pR4pk/1b6/2p5/N1p5/8/PP1r2PP/6K1 b - - 0 1 Analysis by Glaurung Mainz: 1...Rd6 2.Nc3 ² (0.51) Depth: 2/6 00:00:00 1...Rd1+ 2.Kf2 Rd6 ² (0.35) Depth: 2/10 00:00:00 1...Rd1+ 2.Kf2 Rd2+ 3.Kf3 Rd6 ² (0.45) Depth: 3/11 00:00:00 1...Rd6 2.Nc3 Rd2 ² (0.29) Depth: 3/11 00:00:00 1...Rd6 2.Kf2 Rf6+ 3.Ke3 Kg6 ² (0.43) Depth: 4/14 00:00:00 1...Kh6 2.Kf1 Rd1+ 3.Ke2 Rd6 ² (0.34) Depth: 4/14 00:00:00 1...Kg6 2.Kf1 Rd1+ 3.Ke2 Rd6 ² (0.32) Depth: 4/14 00:00:00 1...Kg6 2.Kf1 Rd6 3.Ke2 Kf6 ² (0.28) Depth: 5/14 00:00:00 1...Kg6 2.g3 Rd1+ 3.Kf2 Rd6 4.Ke3 Kf6 ² (0.35) Depth: 6/16 00:00:00 18kN 1...Rxb2 2.Nxb2 c3 3.Rxb6 axb6 4.Nc4 = (0.20) Depth: 6/17 00:00:00 29kN 1...Rxb2 2.Nxb2 c3 3.Nd3 c4+ 4.Rxb6 axb6 5.Nb4 = (0.17) Depth: 7/17 00:00:00 33kN 1...Bd8 2.Rxa7 Bf6 3.Rc7 Bd4+ 4.Kf1 Rf2+ 5.Ke1 Rxg2 = (0.14) Depth: 7/21 00:00:00 59kN 1...Bd8 2.Rxa7 Bf6 3.Rb7 Bd4+ 4.Kf1 Rf2+ 5.Ke1 Rxg2 6.h3 = (0.01) Depth: 8/21 00:00:00 84kN 1...Rxb2 2.Nxb2 c3 3.Nd3 c4+ 4.Rxb6 axb6 5.Nb4 b5 ³ (-0.28) Depth: 8/21 00:00:01 106kN 1...Rxb2 2.Nxb2 c3 3.Rxb6 axb6 4.Nd3 c4 5.Nb4 b5 ³ (-0.28) Depth: 9/21 00:00:01 125kN 1...Rxb2 2.Nxb2 c3 3.Rxb6 axb6 4.Nd3 Kg6 5.Kf2 Kf5 6.Ke3 = (-0.06) Depth: 10/23 00:00:01 171kN 1...Rxb2 2.Nxb2 c3 3.Rxb6 axb6 4.Nd3 c4 5.Nb4 b5 6.Nc2 Kg6 = (-0.10) Depth: 11/24 00:00:01 327kN 1...Bd8 2.Kf1 Bf6 3.h3 Kg6 4.g4 Bd4 5.Rxa7 Bxb2 6.Ra6+ Bf6 7.Nxc5 = (-0.17) Depth: 11/30 00:00:01 988kN 1...Bd8 2.Kf1 Bf6 3.h3 Kg6 4.Rxa7 Bxb2 5.Nxb2 c3 6.Ra6+ Kh7 7.Nc4 c2 8.Nxd2 c1Q+ 9.Ke2 = (-0.25) Depth: 12/30 00:00:02 1564kN 1...Bd8 2.Kf1 Bf6 3.h3 Kg6 4.Rxa7 Bxb2 5.Nxb2 c3 6.Nc4 c2 7.Nxd2 c1Q+ 8.Ke2 Qg1 9.Kf3 = (-0.25) Depth: 13/30 00:00:03 2415kN 1...Bd8 2.g3 Bf6 3.Kh1 Bd4 4.a3 Kg6 5.Nc3 Bxc3 6.bxc3 Rd3 7.Rb5 Rxc3 8.Rxc5 = (-0.21) Depth: 14/31 00:00:07 5603kN 1...Bd8 2.g3 Bf6 3.Kh1 Bd4 4.a3 Kg6 5.Rd7 a5 6.Rb7 Rd1+ 7.Kg2 Rb1 8.Rb6+ Kf5 9.Rb8 Bf6 = (-0.21) Depth: 15/31 00:00:12 8850kN 1...Rxb2 2.Nc3 Rc2 3.Ne4 c3 4.Kf1 Kg6 5.Re7 Rxg2 6.Kxg2 c2 7.Re6+ Kf5 8.Rxb6 c1Q 9.Ng3+ Ke5 10.Rc6 -+ (-2.68) Depth: 15/35 00:00:24 17695kN (, 16.11.2005)
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