Author: Rory Nolan
Date: 02:08:25 09/16/02
Go up one level in this thread
On September 16, 2002 at 03:21:53, Peter McKenzie wrote:
>On September 15, 2002 at 17:10:00, Jim Monaghan wrote:
>
>>Hi,
>>
>>Here's an interesting game played in Leo's AmCom tournament. Although Gandalf
>>won the match 3-1, Zarkov had the satisfaction of taking the last game in pretty
>>fashion with a positional queen sacrifice where Zarkov's pieces overcame
>>Gandalf's lady.
>>
>>
>>[Event "AmCom_2"]
>>[Site "DUAL-P3-1266"]
>>[Date "2002.09.05"]
>>[Round "1.4"]
>>[White "Gandalf 5.1"]
>>[Black "Zarkov 4.5y"]
>>[Result "0-1"]
>>
>>1. d4 Nf6 2. Nf3 g6 3. c4 Bg7 4. Nc3 d5 5. Qb3 dxc4 6. Qxc4
>>O-O 7. e4 a6 8. e5 b5 9. Qb3 Nfd7 10. Be3 c5 11. dxc5 Nxe5
>>12. Nxe5 Bxe5 13. Rd1 Qa5 14. Bd2 Be6 15. Nd5 Qd8 16. Bh6
>>Nc6 17. Nf6+ Bxf6 18. Rxd8 Rfxd8 19. Qa3 b4 20. Qa4 Bd5
>>21. Qc2 Nd4 22. Qc1 Rac8 23. Be3 Rc6 24. Rg1 Rdc8 25. Qd1
>>Rxc5 26. Bxa6 Nc2+ 27. Ke2 Nxe3 28. Kxe3 R8c6 29. Bd3 Re6+
>>30. Kf4 Be5+ 31. Kg4 Rf6 32. Kh4 g5+ 33. Kh5 Kg7 34. f4
>>Rxf4 35. Qg4 Rxg4 36. Kxg4 Bxa2 37. Ra1 Be6+ 38. Kf3 Bxb2
>>39. Rb1 {White resigns} 0-1
>>
>>There are two interesting decision points. The first one is here:
>>
>>[D] rn1q1rk1/4pp1p/p3b1pB/1pPNb3/8/1Q6/PP3PPP/3RKB1R b K -
>>
>>Most engines will want to play 16...Qa5+ here with a possible line of 17.Bd2 Qd8
>>and a repitition. Not Zarkov, 16...Nc6 is an enterprising move. I've found some
>>engines will play this move as well.
>
>On my 1Ghz machine, Warp switches to Nc6 after about 10 seconds and sticks with
>it for a couple of minutes at least.
>
>>
>>The next position is even more intriguing.
>>
>>[D] r2R1rk1/4pp1p/p1n1bbpB/1pP5/8/1Q6/PP3PPP/4KB1R b K -
>>
>>Here most engines want to play 16...Bxb3 with this idea: 19. Rxf8+ Rxf8 20.
>>Bxf8 Bxa2 21. Bh6 Bxb2. Black has a N+2Ps against a WR. The two pawns are
>>connected passers on the queenside. White's c-pawn is safely blockaded and is
>>way behind in development. Rooks can wreck havoc in the endgame however. Can
>>White untangle himself in time or is the position a win for Black? (Rhetorical
>>question.) Black looks clearly better, whether it's a win or not ... is another
>>matter.
>
>Warp prefers Bxb3, giving almost 1 pawn advantage (probably optimistic).
>If I force Rfxd8 the score favours black buy about 0.3 of a pawn after a minute.
>
>>
>>I guess it's a question of style as to how to proceed. Zarkov's 16...Rfxd8 is
>>certainly strong as well only in a different way. The game is kept in the
>>middlegame and turns into an uneven battle between Black's well co-ordinated
>>forces against Gandalf's queen. The eval slowly creeps up as one progresses
>>through the game and only then do most engines realize that Black is better here
>>in this second line.
>>
>>Only Crafty, of the freely available engines I tested, like Zarkov's move. The
>>others all perfer the more prosaic endgame alternative which seems a strong line
>>as well, if not as enterprising.
>>
>>In the second position, does any other program, besides Zarkov and Crafty perfer
>>the middlegame approach?
>>
>>Cheers,
>>Jim
Here's analysis from Junior 7 on an XP 1900+ 128 mb for hash
New game
r2R1rk1/4pp1p/p1n1bbpB/1pP5/8/1Q6/PP3PPP/4KB1R b K - 0 1
Analysis by Junior 7:
1...b4 2.Qxe6 fxe6
+- (4.70) Depth: 3 00:00:00
1...Nxd8 2.Qf3 Rc8 3.Bxf8
+- (2.16) Depth: 3 00:00:00
1...Bxb3 2.Rxf8+ Rxf8 3.Bxf8 Kxf8
² (0.50) Depth: 3 00:00:00 1kN
1...Bxb3 2.Rxf8+ Rxf8 3.Bxf8 Bxa2 4.Bh6 Bxb2
= (-0.09) Depth: 6 00:00:00 3kN
1...Bxb3 2.Rxf8+ Rxf8 3.Bxf8 Bxa2 4.Bh6 Bxb2
= (-0.09) Depth: 6 00:00:00 3kN
1...Bxb3 2.Rxf8+ Rxf8 3.Bxf8 Kxf8 4.axb3 Bd4 5.b4 Bxb2 6.Bd3 Nxb4
= (0.18) Depth: 9 00:00:00 34kN
1...Bxb3 2.Rxf8+ Rxf8 3.Bxf8 Kxf8 4.axb3 Bd4 5.g3 Bxc5 6.Bg2 Bb4+ 7.Kd1 Nd4
8.Bd5
= (-0.09) Depth: 12 00:00:00 361kN
1...Bxb3 2.Rxf8+ Rxf8 3.Bxf8 Bxa2 4.Bh6 Bxb2 5.Bd3 Bd5 6.Kf1 Bd4 7.Be3 Bc3
³ (-0.34) Depth: 15 00:00:03 3036kN
1...Bxb3 2.Rxf8+ Rxf8 3.Bxf8 Bxa2 4.Bh6 Bxb2 5.Bd3 Bd5 6.0-0 Bd4 7.Rc1 Bg7
8.Bxg7 Kxg7
³ (-0.34) Depth: 17 00:00:19 18685kN
1...Bxb3 2.Rxf8+ Rxf8 3.Bxf8 Bxa2 4.Bh6 Bxb2 5.Bd3 Bd5 6.0-0 Bd4 7.Rc1 b4 8.Bxa6
b3 9.Bc4 b2
= (-0.22) Depth: 18 00:01:56 124126kN
1...Rfxd8 2.Qa3 b4 3.Qa4 Bxb2 4.Qxc6 Bc3+ 5.Ke2 Bc4+ 6.Ke3 Bxa2 7.Bd3 Bd5 8.Qb6
a5 9.c6 Bxg2 10.Rd1 Rd5
³ (-0.35) Depth: 18 00:04:15 282838kN
1...Rfxd8 2.Qa3 b4 3.Qa4 Bxb2 4.Qxc6 Bc3+ 5.Ke2 Bc4+ 6.Ke3 Bxa2 7.Bd3 Bd5 8.Qb6
Rac8 9.Rb1 Bxg2 10.Rxb4 Bxb4
³ (-0.31) Depth: 19 00:11:14 741195kN
1...Bxb3 2.Rxf8+ Rxf8 3.Bxf8 Bxa2 4.Bh6 Bxb2 5.Bd3 Bd5 6.0-0 e6 7.Re1 Ba3 8.Be3
Kf8
³ (-0.40) Depth: 19 00:11:31 756039kN
1...Bxb3 2.Rxf8+ Rxf8 3.Bxf8 Bxa2 4.Bh6 Bxb2 5.Bd3 Bd5 6.0-0 e6 7.Re1 Ba3 8.Be3
Bb4 9.Ra1
³ (-0.40) Depth: 20 00:16:05 1047093kN
1...Bxb3 2.Rxf8+ Rxf8 3.Bxf8 Bxa2 4.Bh6 Bxb2 5.Bd3 Bd5 6.0-0 e6 7.Rb1 Bd4 8.Rc1
b4 9.Bxa6 b3 10.Bb5 b2
³ (-0.41) Depth: 21 00:32:51 2105011kN
(Nolan, 16.09.2002)
Rory
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