Author: Albert Silver
Date: 17:38:13 09/11/04
Go up one level in this thread
On September 11, 2004 at 06:30:54, José de Jesús García Ruvalcaba wrote:
>On September 10, 2004 at 17:18:06, Uri Blass wrote:
>
>>I looked at the book secret of chess tactics by mark dvoretsky and in pages
>>94-100 there is a game of Borkowski against nunn that is discussed
>>
>>Nunn claimed after the game that 12...gxf5 could lead to better position for
>>black.
>>
>>The book claims that 13.Nce4!! refutes 12...gxf5 and that the line
>>13.Nce4 fxe4 14.Nxe4 is winning for white.
>>
>>I did not find a convinvcing line against 14...Nb4 or 14...Nc5
>>What does your program say?
>>
>
>Could you please post a diagram for the relevant position?
>José.
[D]r1bq1rk1/pp1nppb1/n7/4ppN1/3p4/2NB4/PPP3P1/R1BQK2R w KQ - 0 13
However, my analysis seems to reach different conclusions and confirm that White
is better if not winning. Still the lines are so deep that it is unlikely anyone
could possibly have found these over the board. I did find one improvement over
one of his lines though.
Up til 13. Nce4 fxe4 14. Nxe4 Nb4 15. Qh5 Nxd3+ 16. cxd3 f6 17. Qg6 there is
little doubt.
[D]r1bq1rk1/pp1np1b1/5pQ1/4p3/3pN3/3P4/PP4P1/R1B1K2R b KQ - 0 17
Then there are 3 main lines:
The shortest is 15... Nxd3+ 16. cxd3 f6 17. Qg6 Nb6 18. Rh7 Rf7 19. Bh6 Qf8 20.
Ng3
[D]r1b2qk1/pp2prbR/1n3pQB/4p3/3p4/3P2N1/PP4P1/R3K3 b Q - 0 20
which is completely winning position for White.
And the next line, where I found an improvement over Uri's main line:
17... Rf7 18. Qh7+ Kf8 19. Bh6 Qa5+
[D]r1b2k2/pp1nprbQ/5p1B/q3p3/3pN3/3P4/PP4P1/R3K2R w KQ - 0 20
However, instead of 20. Kf2? Ke8 21. Bxg7 Nf8 22. Qh5
[D]r1b1kn2/pp2prB1/5p2/q3p2Q/3pN3/3P4/PP3KP1/R6R b - - 0 22
which allows Black to get away with a draw at the very worse with 22...f5! 23.
Ng5 24. Qd2+
20. Kf1!! seems to be winning, but the lines are so deep that as said, even
though it may be an objective win, I don't know how findable this all would be.
The key difference is that there is no check on d2 after f5, and after
20...Qb5!? 21. Kg1 allows the rook to enter on f1 with devastating effect,
though don't expect the engines to see this anytime soon BTW.
23. Kg1 Qxb2 24. Rf1 Be6 25. Bxf8 Qxa2 26. Qg6 Kd7
[D]r4B2/pp1kpr2/4bpQ1/4p3/3pN3/3P4/q5P1/5RKR w - - 0 27
Now the Black king is in big trouble:
27. Bxe7 Rxe7 28. Rh7! (trading off the defending rook) Rg8 29. Nxf6+ Kd6 30.
Nxg8 Rxh7 31. Qxh7 Bxg8
[D]6b1/pp5Q/3k4/4p3/3p4/3P4/q5P1/5RK1 w - - 0 32
Although it may seem that Black has managed to survive, but the queen and rook
are able to mop up the rest:
32. Qxb7 Bd5 33. Rf6+ Kc5 34. Qe7+ Kb5 35. Rf2 Qb1+ 36. Kh2 Qxd3 (36... Qc1 37.
Qe8+ Qc6 38. Qb8+ Ka6 39. Qf8 Qc3 40. Qd6+ Bc6 41. Qc7 Ba4 42. Rf6+ Kb5 43. Qb7+
Kc5) 37. Rb2+ Bb3 38. Qa3 Kc6 39. Rxb3 *
Albert
Below is the PGN with my added lines:
[Event "10'/40"]
[Site "Private"]
[Date "2004.09.10"]
[Round "?"]
[White "Dvoretsky"]
[Black "Uri"]
[Result "*"]
[ECO "B09"]
[Annotator ""]
[PlyCount "77"]
[TimeControl "40/600:0"]
{512MB, Fritz8.ctg, URI-AMD} 1. e4 g6 2. d4 Bg7 3. Nc3 d6 4. f4 Nf6 5. Nf3 O-O
6. Bd3 Na6 7. e5 Nd7 8. h4 c5 9. h5 cxd4 10. hxg6 hxg6 11. Ng5 dxe5 12. f5 gxf5
13. Nce4 fxe4 14. Nxe4 Nb4 (14... Nac5) 15. Qh5 (15. Bc4 Nd5 16. Bh6 (16. Qh5
N7f6 17. Qh4 Bf5 18. Bh6 Ng4 19. Bxg7 Kxg7 20. Qg5+ Bg6 21. Qxg4) 16... Bxh6 (
16... N7f6 17. Nxf6+ Nxf6 18. Bxg7 Qa5+ 19. c3 dxc3 20. b4 Qxb4 21. Bxf8 Qxc4
22. Bxe7 Qe4+) 17. Rxh6 N7f6 18. Nxf6+ Nxf6 19. Qd2 Nh7 20. O-O-O Bf5 21. Rdh1
e6 22. Rxh7 Qf6 23. R7h6 Qg7 24. g4 Be4 25. R1h5 Bg6 26. Rh8+ Qxh8 27. Rxh8+
Kxh8 28. Qh6+ Kg8 29. Bxe6 Bxc2 30. Kxc2 fxe6 31. Qxe6+ Kh7 32. Qxe5 Rf2+ 33.
Kb3 Raf8 34. Qe4+ Kg8 35. Qg6+ Kh8 36. g5 Rh2) 15... Nxd3+ 16. cxd3 f6 17. Qg6
Rf7 (17... Nb6 18. Rh7 Rf7 19. Bh6 Qf8 20. Ng3) 18. Qh7+ Kf8 19. Bh6 Qa5+ 20.
Kf1 (20. Kf2 Ke8 (20... e6 21. Nd6 Qb4 22. Nxf7 Bxh6) 21. Bxg7 Nf8 22. Qh5 f5
23. Ng5 Qd2+) 20... Ke8 21. Bxg7 Nf8 22. Qh5 Qb5 (22... f5) 23. Kg1 Qxb2 24.
Rf1 Be6 (24... Qxa2 25. Bxf8) 25. Bxf8 Qxa2 26. Qg6 Kd7 27. Bxe7 Rxe7 (27...
Kxe7 28. Rh7 Raf8 29. Qxf6+ Ke8 30. Nd6+) 28. Rh7 Rg8 29. Nxf6+ Kd6 30. Nxg8
Rxh7 31. Qxh7 Bxg8 32. Qxb7 Bd5 33. Rf6+ Kc5 34. Qe7+ Kb5 35. Rf2 Qb1+ 36. Kh2
Qxd3 (36... Qc1 37. Qe8+ Qc6 38. Qb8+ Ka6 39. Qf8 Qc3 40. Qd6+ Bc6 41. Qc7 Ba4
42. Rf6+ Kb5 43. Qb7+ Kc5) 37. Rb2+ Bb3 38. Qa3 Kc6 39. Rxb3 *
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