Author: Uri Blass
Date: 08:51:16 09/28/01
Go up one level in this thread
On September 27, 2001 at 18:02:03, Dann Corbit wrote: >On September 27, 2001 at 17:47:47, Robert Hyatt wrote: > >>On September 27, 2001 at 17:33:58, Roy Eassa wrote: >> >>>On September 27, 2001 at 17:07:23, Andy Serpa wrote: >>> >>>>I am intrigued by this position from an old book: >>>> >>>>[D]rnb2r1k/pp1p2pp/2p1P3/2q1p3/2B3Q1/2N4P/PPP3P1/R1B4K w - - 0 1 >>>> >>>> >>>>In the book, White saves himself with the following manoeuvre: >>>> >>>>1. b4 Qxb4 2. Rb1 Qxc3 3. Bh6 gxh6 4. e7 Re8 5. Rf1 >>>>and white mates in a few moves. >>>> >>>> >>>>I'm curious what a fast computer comes up with in this position... >>> >>> >>>Starting two moves in (I think it's too hard to start at the beginning), after >>>1. b4 Qxb4 2. Rb1 Qxc3: >>> >>>[D]rnb2r1k/pp1p2pp/2p1P3/4p3/2B3Q1/2q4P/P1P3P1/1RB4K w - - 0 1 >>> >>>Here's what I get with Gambit Tiger 2.0 Aggressive on an Athlon 1.2 (in 1 >>>minute, it sees it has a perpetual. In 1.5 minutes, it sees it has an >>>advantage. In 4 minutes, it sees it has a win.): >>> >>>00:00:00.8 -4.14 8 161550 Bd3 Qe1+ Kh2 Qf2 e7 Re8 Bxh7 Rxe7 Bg6 >>>00:00:00.1 -3.24 8 312659 Bd3 >>>00:00:01.7 -3.24 9 391208 Bd3 Qe1+ >>>00:00:01.4 -3.68 9 670505 Bd3 Qc5 Qh4 e4 Qxe4 Qh5 e7 Re8 Ba3 d5 >>>00:00:02.2 -3.02 9 885911 e7 Re8 Bh6 gxh6 Rf1 Qa3 Rf7 Qc1+ Kh2 Qf4+ Rxf4 exf4 >>>00:00:05.0 -2.12 10 2037930 e7 >>>00:00:06.5 -2.12 11 2496977 e7 >>>00:00:11.9 -1.60 11 4422079 e7 Re8 Bd3 d5 Qf3 Nd7 Qf7 Rxe7 Qxe7 Qc5 Qe6 Qf8 Bb2 >>>00:00:14.9 -1.60 12 5492547 e7 Re8 >>>00:00:48.3 -1.36 12 17494341 Bd3 Qe1+ Kh2 Rf1 Bxf1 Qxf1 Ba3 Qf6 e7 Qf7 Rf1 Qg8 >>>Qf5 >>>00:00:55.1 -0.70 12 20234211 Bh6 >>>00:00:57.8 -0.31 12 21078455 Bh6 gxh6 e7 Re8 Rf1 Qa3 Rf7 Qc1+ Kh2 Qg5 Rf8+ Kg7 >>>Rf7+ Kg8 Rf8+ Kg7 >>>00:01:33.7 0.59 13 35309917 Bh6 >>>00:04:00.9 3.84 13 94628156 Bh6 Rg8 e7 Qxc4 Qxc4 d5 Bxg7+ Kxg7 Qh4 Nd7 Qg5+ Kf7 >>>Rf1+ Ke6 Qxg8+ Kxe7 Rf7+ Kd6 >> >> >>I think that is too late to start searching. Qc3 probably loses. Question is, >>is there an alternative that doesn't, such as Qa3 instead. I haven't studied it >>much, but the queen at c3 is locked out of the game which is how white wins. > >After b4, I think Qf2 is white's best move. It's still bad, but not a clear >loser like Qxb4. From what I have seen so far, all the programs I have tested >snack on the pawn and have no idea of the trouble in store. They have a big, >fat, positive eval after taking the pawn, even after a nice long think about it. > >A terrific test position! Actually several of them. (bm b4, am Qxb4... maybe >more!) I disagree b4 is probably a mistake when Qxb4 is the right move Here is Deep Fritz's analysis after b4 Qxb4 Rb1 New position [D]rnb2r1k/pp1p2pp/2p1P3/4p3/1qB3Q1/2N4P/P1P3P1/1RB4K b - - 0 1 Analysis by Deep Fritz: 2...Qxc3 3.Qe4 dxe6 4.Bb2 Rf4 5.Bxc3 -+ (-6.47) Depth: 5/17 00:00:00 14kN 2...Qxc3 3.Qe4 dxe6 4.Bb2 Rf4 5.Bxc3 -+ (-6.47) Depth: 5/17 00:00:00 14kN 2...Qxc3 3.Qe4 dxe6 4.Bb2 Rf4 5.Bxc3 -+ (-6.47) Depth: 5/17 00:00:00 14kN 2...Qxc3 3.Qe4 dxe6 4.Bb2 Rf4 5.Bxc3 -+ (-6.47) Depth: 5/17 00:00:00 14kN 2...Qxc3 3.Qe4 dxe6 4.Bb2 Rf4 5.Bxc3 -+ (-6.47) Depth: 5/17 00:00:00 14kN 2...Qxc3 3.Qe4 dxe6 4.Bb2 Rf4 5.Bxc3 -+ (-6.47) Depth: 5/17 00:00:00 14kN 2...Qxc3 3.Qe4 dxe6 4.Bb2 Rf4 5.Bxc3 -+ (-6.47) Depth: 5/17 00:00:00 14kN 2...Qxc3 3.Qe4 dxe6 4.Bb2 Rf4 5.Bxc3 -+ (-6.47) Depth: 5/17 00:00:00 14kN 2...Qxc3 3.Qe4 dxe6 4.Bb2 Rf4 5.Bxc3 -+ (-6.47) Depth: 5/17 00:00:00 14kN 2...Qxc3 3.Qe4 dxe6 4.Bb2 Rf4 5.Bxc3 -+ (-6.47) Depth: 5/17 00:00:00 14kN 2...Qxc3 3.Bd3 dxe6 4.Qh4 h6 5.Be3 -+ (-6.31) Depth: 6/19 00:00:00 42kN 2...Qxc3-- -+ (-6.00) Depth: 7/18 00:00:00 75kN 2...Qxc3-- 3.e7 Re8 4.Bb2 Qd2 5.Rf1 Qd6 -+ (-5.41) Depth: 7/22 00:00:00 137kN 2...Qxc3 3.e7 Re8 4.Bb2 Qd2 5.Rf1 Qd6 6.Rf8+ Rxf8 -+ (-5.28) Depth: 8/20 00:00:00 194kN 2...Qxc3 3.e7 Re8 4.Bb2 Qa5 5.Rf1 Qb4 6.Bxe5 Qxe7 -+ (-5.22) Depth: 9/25 00:00:00 439kN 2...Qxc3-- -+ (-4.91) Depth: 10/22 00:00:01 547kN 2...Qxc3-- 3.e7 Re8 4.Bb2 Qb4 -+ (-4.72) Depth: 10/30 00:00:01 908kN 2...Qxc3-- -+ (-4.41) Depth: 11/25 00:00:02 1349kN 2...Qxc3-- 3.e7 Re8 4.Bh6 gxh6 5.Rf1 Qa3 6.Rf7 Qc1+ 7.Kh2 Qg5 8.Rf8+ -+ (-3.53) Depth: 11/34 00:00:09 5884kN 2...Qxc3-- -+ (-3.22) Depth: 12/28 00:00:16 10286kN 2...Qxc3-- 3.Bd3 Qe1+ 4.Kh2 Rf1 5.Bxf1 Qxf1 6.Ba3 Qf6 7.e7 Qf7 8.Re1 -+ (-3.00) Depth: 12/38 00:00:48 30032kN 2...Qxc3 3.e7 Re8 4.Bh6 gxh6 5.Rf1 Qa3 6.Rf7 Qc1+ 7.Kh2 Qf4+ 8.Qxf4 -+ (-3.00) Depth: 13/36 00:01:42 64410kN 2...Qxc3-- -+ (-2.69) Depth: 14/34 00:02:00 76124kN 2...Qxc3-- 3.Bd3 dxe6 4.Qh4 Qxd3 5.cxd3 Rf1+ 6.Kh2 Kg8 7.Qg3 c5 8.Bh6 ³ (-0.59) Depth: 14/42 00:04:57 187392kN 2...Qe7! ³ (-0.63) Depth: 14/42 00:05:45 221054kN 2...Qe7! 3.Bg5 Qe8 4.e7 d5 5.exf8Q+ Qxf8 µ (-1.25) Depth: 14/42 00:12:47 464376kN 2...Qe7 3.Bg5 Qe8 4.e7 d5 5.exf8Q+ Qxf8 6.Qe2 dxc4 7.Rf1 Qg8 8.Qxe5 µ (-1.25) Depth: 15/37 00:16:50 620821kN 2...Qe7 3.Bg5 Qe8 4.e7 d5 5.exf8Q+ Qxf8 µ (-1.25) Depth: 16/40 00:24:15 923445kN 2...Qe7 3.Bg5 Qe8 4.e7 d5 5.exf8Q+ Qxf8 6.Qe2 dxc4 7.Rf1 Qg8 8.Qxe5 µ (-1.13) Depth: 17/42 00:46:03 1826152kN 2...Qe7 3.Bg5 Qe8 4.e7 d5 5.exf8Q+ Qxf8 µ (-1.13) Depth: 18/45 01:57:18 4790291kN 2...Qe7 3.Bg5 Qe8 4.Qh4 d5 5.Bd3 e4 6.Nxe4 dxe4 7.Bxe4 µ (-1.03) Depth: 19/47 05:26:56 13588709kN 2...Qe7 3.Bg5 Qe8 4.Qh4 d5 5.Bd3 e4 6.Nxe4 dxe4 7.Bxe4 µ (-0.91) Depth: 20/47 12:54:03 32973574kN (Blass, Tel-aviv 28.09.2001) Uri
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