Author: John Merlino
Date: 21:26:11 11/18/02
Go up one level in this thread
On November 18, 2002 at 18:40:58, Roy Eassa wrote: >On November 18, 2002 at 17:46:35, Roy Eassa wrote: > >>White to move and win: >> >>[d] 8/6N1/K2k3B/4p3/8/p7/2PP4/8 w - - 0 1 >> >>This is from Pal Benko, an improvement on a study by L. Kubbel. It was in the >>current issue of Chess Life magazine. >> > > >Here is a more difficult variation on the theme, also from Benko. This one is >suitable for modern PCs/programs. > >Black to move but White to win: > >[d] K7/8/p7/3k4/3p4/8/2PP1B2/8 b - - 0 4 > >(Sorry about the move numbers starting at 4 instead of 1; I don't know how to >reset that value without wiping out all the analysis.) > >4...d3 > > [or 4...a5 5.d3! > (5.Bh4? d3! 6.c3 a4 7.Be7 Kc4 8.Kb7 Kb3 9.Kb6 Kc2 10.c4 Kxd2 11.c5 Ke2 =) > 5...a4 6.Bh4 a3 7.Bf6 a2 8.c4+ Kc5 9.Kb7 a1Q 10.Be7#] > > [or 4...Kc4 5.Kb7 a5 > (5...d3 6.c3 a5 7.Kc6 a4 8.Bc5 Kb3 9.Kb5 +-) > 6.Kc6 d3 > (6...a4 7.d3+ Kc3 8.Kc5 +-) > 7.c3 a4 8.Bc5 Kb3 9.Kb5 +-] > >5.c4+! > > [5.c3? a5 6.Bh4 a4 7.Be7 Kc4 8.Kb7 Kb3 9.Kb6 Kc2 10.c4 Kxd2 11.c5 Ke2 =] > > [5.cxd3? a5 =] > >5...Kxc4 6.Bb6 Kb5 7.Bd4 > > [or 7.Kb7 a5 8.Bd4, which transposes] > >7...a5 8.Kb7 a4 9.Kc7 > > [or 9.Bb2 Kb4 10.Kc6 Kb3 11.Bc3 Kc4 12.Kd6 +- as in other lines] > >9...Kc4 10.Bc3 Kc5 > > [10...a3 11.Kd6 a2 12.Ke5 Kb3 13.Kd4 Kc2 14.Ke3 +-] > >11.Bb2 Kd5 12.Kb6 Kc4 13.Kc6 Kb3 14.Bc3 Kc4 15.Kd6 a3 16.Ke5 Kb3 >17.Kd4 Kc2 18.Ke4 a2 19.Ke3 +- > > >After Black's clever first move of ...d3, how long does it take for your program >to realize that White's only win is with c4+ ? In the first position, it takes Chessmaster 9000, on a P3-733, 22 seconds to find 1...d3: Time Depth Score Positions Moves 0:00 3/7 2.20 10517 4...a5 5.Bh4 Ke6 6.Kb7 a4 7.c4 dxc3ep 8.dxc3 0:00 4/8 2.01 21957 4...a5 5.Bh4 Ke6 6.c3 dxc3 7.dxc3 a4 8.Kb7 a3 9.c4 0:00 5/9 2.00 43358 4...a5 5.Bh4 Ke6 6.Kb7 a4 7.Bf2 Kd5 8.c3 dxc3 9.dxc3 0:00 6/10 1.92 69208 4...a5 5.Bh4 Ke6 6.Kb7 a4 7.Kc6 a3 8.Bf2 Ke5 9.Kc5 0:01 7/11 2.15 138868 4...a5 5.Bh4 d3 6.c3 Kd6 7.Kb7 a4 8.Bf2 a3 9.c4 a2 10.c5+ Kd5 0:02 8/12 2.15 285982 4...a5 5.Bh4 d3 6.c3 Kd6 7.Kb7 a4 8.Bf6 a3 9.c4 a2 10.Bd4 Kd7 11.c5 0:03 9/13 2.15 438398 4...a5 5.Bh4 d3 6.c3 Ke6 7.Kb7 a4 8.c4 a3 9.Bf2 a2 10.Bd4 Kd7 11.c5 0:05 10/14 1.80 728327 4...a5 5.Bh4 d3 6.c3 Kc4 7.Be7 a4 8.Kb7 Kb3 9.Kc6 Kc2 10.Bg5 Kb2 11.Kd5 a3 0:08 11/15 2.04 1205329 4...a5 5.Bh4 d3 6.c3 Kc4 7.Be7 a4 8.Kb7 Kb3 9.Kb6 Kc2 10.Bg5 Kb3 11.Kc5 a3 12.Kd4 0:16 12/16 1.82 2309063 4...a5 5.d3 a4 6.Bh4 Ke6 7.Bg5 a3 8.Bc1 a2 9.Bb2 Ke5 10.Kb8 Kd5 11.Ba1 Ke5 12.Kc7 Kd5 0:22 12/16 1.09 3299410 4...d3 5.c3 a5 6.Bh4 Kc4 7.Kb7 a4 8.Be7 Kb3 9.Kb6 Kc2 10.Kb5 Kxd2 11.Bb4 Ke2 12.Kxa4 d2 0:26 13/17 0.95 3840207 4...d3 5.c3 a5 6.Bh4 Kc4 7.Kb7 a4 8.Be7 Kb3 9.Kb6 Kc2 10.Kb5 Kxd2 11.Bb4 Kc2 12.c4 Kb3 0:33 14/18 0.49 4907481 4...d3 5.c3 a5 6.Bh4 Kc4 7.Kb7 a4 8.Be7 Kb3 9.c4 Kxc4 10.Kc6 Kb3 11.Kd5 Kc2 12.Bb4 a3 13.Kd4 a2 After forcing 4...d3, it takes 31 seconds to find 5.c4+: Time Depth Score Positions Moves 0:00 5/9 1.92 27226 5.cxd3 a5 6.Kb7 a4 7.Kc7 a3 8.Bh4 Kd4 9.Bf6+ Kxd3 0:00 5/9 2.04 31287 5.c3 a5 6.Bh4 Kd6 7.Bf6 a4 8.Bg7 Kd5 9.Bf8 0:00 6/10 2.12 53814 5.c3 a5 6.Bh4 Ke6 7.Kb7 a4 8.c4 a3 9.Bf2 a2 10.Bd4 Kd7 0:00 7/11 2.12 84193 5.c3 a5 6.Bh4 Ke6 7.Kb7 a4 8.c4 a3 9.Bf2 Kd7 10.Bd4 a2 0:01 8/12 2.15 150565 5.c3 a5 6.Bh4 Ke6 7.Kb7 a4 8.c4 a3 9.Bf2 a2 10.Bd4 Kd7 11.c5 0:01 9/13 1.80 259903 5.c3 a5 6.Bh4 a4 7.Be7 Kc4 8.Kb7 Kb3 9.Kc6 Kc2 10.Bg5 Kb2 11.Kd5 a3 0:03 10/14 1.67 422942 5.c3 a5 6.Bh4 a4 7.Be7 Kc4 8.Kb7 Kb3 9.Bd6 Kc2 10.Bf4 Kb3 11.Kc6 a3 12.Kd5 0:04 11/15 1.09 691013 5.c3 a5 6.Bh4 a4 7.Be7 Kc4 8.Kb7 Kb3 9.Bb4 Kc2 10.Kc6 Kxd2 11.Kb5 Ke2 12.Kxa4 d2 0:08 12/16 0.95 1236503 5.c3 a5 6.Bh4 Kc4 7.Kb7 Kb3 8.Kb6 a4 9.Be7 Kc2 10.Kb5 Kxd2 11.Bb4 Kc2 12.c4 Kb3 0:14 13/17 0.49 2146136 5.c3 a5 6.Bh4 Kc4 7.Kb7 a4 8.Be7 Kb3 9.c4 Kxc4 10.Kc6 Kb3 11.Kd5 Kc2 12.Bb4 a3 13.Kd4 a2 0:25 14/18 0.14 3599584 5.c3 a5 6.Bh4 Kc4 7.Kb7 a4 8.Be7 Kb3 9.c4 Kxc4 10.Kc6 Kb3 11.Kd7 a3 12.Bxa3 Kxa3 13.Kc6 Kb3 14.Kd5 Kc2 0:31 14/18 0.95 4596705 5.c4+ Kxc4 6.Bb6 Kb5 7.Bd4 a5 8.Bb2 a4 9.Kb7 Kc4 10.Kc6 Kb3 11.Bc3 Kc4 12.Kd6 a3 13.Ke5 Kc5 14.Ba1 a2 0:36 15/19 0.96 5398165 5.c4+ Kxc4 6.Bb6 Kb5 7.Bd4 a5 8.Bb2 a4 9.Kb7 Kc4 10.Kc6 Kb3 11.Bc3 Kc4 12.Kd6 a3 13.Ke5 Kc5 14.Ke4 Kc4 15.Ba1 jm
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