Wednesday, February 25, 2009

Sometimes a grandmaster...sometimes a BDG

Sometimes a grandmaster who normally wouldn't consider playing the white side of a Blackmar-Diemer plays one anyway--by transposition. We all have seen that.

Take for example the so-called Pöhlmann Defense to the BDG. After 1.d4 d5 2.e4 dxe4 3.Nc3 Black foregoes the usual 3...Nf6 for 3...f5, resulting in a position that is also reached in the Dutch Defense via 1. d4 f5 2. Nc3 d5 3. e4 dxe4

GM Eric Lobron is inactive (on the chessboard) these days. At his peak in mid-1992 he had an ELO of 2625 and was 20th in the world. He twice won the German championships, in 1982 and 1984. Here's his BDG by other means.

Eric Lobron (2585) - Christian Bauer (2465)
Bundesliga, Germany 1996
BDG, Pöhlmann Defense from Dutch Defense

1. d4 f5 2. Nc3 d5 3. e4 dxe4 4. Bf4 Nf6 5. f3 a6 6. Qd2 Nc6 7. O-O-O e6 8. fxe4 fxe4 9. Nge2 Be7 10. g3 e5 11. dxe5 Qxd2+ 12. Rxd2 e3 13. Bxe3 Nxe5 14. Bf4 Bd6 15. Bg2 O-O 16. Nd5 Rb8 17. Nec3 Nh5 18. Ne7+ Bxe7 19. Bxe5 Bg5 20. Bd5+ Kh8 21. Bxc7 Ra8 22. Ne4 Bxd2+ 23. Kxd2 Bg4 24. Ng5 Rf2+ 25. Ke3 Raf8 26. h3 Bc8 27. g4 Rxc2 28. Bd6 Re8+ 29. Kd3 Nf6 30. Nf7+ Kg8 31. Nh6+ 1/2-1/2

Actually, that game was just an excuse to sneak in my own BDG with Lobron. The encounter is memorable to me, not just because my opponent went on to such great achievements within a few short years, but also because the game was my first tournament Blackmar-Diemer.

Tom Purser - Eric Lobron
Heidelberg, 1977
BDG, Teichmann Defense

1. d4 d5 2. e4 dxe4 3. Nc3 Nf6 4. f3 exf3 5. Nxf3 Bg4 6. h3 Bh5 7. g4 Bg6 8. Bc4 e6 9. Ne5 Bb4 10. Bg5 Be4 11. O-O Bxc3 12. bxc3 h6 13. Bh4 Bd5 

14. Bd3

14. Bxd5 Qxd5 15. Bxf6 gxf6 16. Rxf6 Nd7 17. Nxd7 Qxd7 18. Qf3 would have been better, but I was probably afraid of the half-open g-file.

14... Nbd7 15. c4 Bc6 16. Qe1 Nxe5 17. Qxe5 Nxg4 18. Qxg7 Qxh4 19. Qxh8+ Ke7 20. Rxf7+ Kxf7 21. Rf1+ Nf6 22. Qh7+ Kf8 23. Qh8+ Kf7 24. Qh7+ Ke8

25. Bg6+?

25. Qg6+ Ke7 26. Qg7+ Kd6 27. Rxf6 Qxd4+ (27... Qxh3?? 28. c5+ Kd5 29. Rf5+ exf5 30. Qe5#) 28. Kf1 and Black would have had to work.

25... Kd8 26. Qh8+ Ne8 27. d5 Qg3+ 28. Kh1 Qxh3+ 29. Kg1 Qg3+ 30. Kh1 Qxg6 and 0-1 in a few more moves.

Friday, February 20, 2009

A Ryder's Gambit in the Wizard's Castle

Today in his blog, The Wizard's Castle, Eric Shoemaker annotates a Blackmar-Diemer he won in the Reno Club Championship Qualifier:
"I knew I would be facing the speculative 'Blackmar-Diemer Gambit' but was more prepared for one variation than the other. This led to me getting into some difficulties early on, in which I should have lost. I did not lose, however, as I went in for really sharp play with 29...Qd8! But it's possible that I'm still lost with best play after this move; however, it was the only feasible possibility in the position. Alternatives did not seem to offer any chances of success."
Here's the game and my take on it, with a little help from Rybka. You can find Eric's notes here. David Cater (2000) - Eric Shoemaker (1850) Reno, Nevada Club Championship Qualifier, 19 Feb 2009 Blackmar-Diemer Gambit, Ryder Gambit 1. d4 d5 2. e4 dxe4 3. Nc3 Nf6 4. f3 exf3 5. Qxf3 g6 6. Be3 Bg7 7. O-O-O c6 8. h3 O-O 9. Bc4 Qa5 10. g4 e6 11. Nge2 Nbd7 12. h4 Nb6 13. Bb3 Nbd5 14. Bg5 Nxc3 15. Nxc3 Nd5 16. Nxd5 exd5 17. h5 Be6 18. h6
18...Bxg4 Black panicked, concerned with his black-square weakness. But better was 18... Bh8 19. Bf6 Bxg4 20. Qf4 Bxd1 21. Rxd1 Rae8 22. Bxh8 Re6 19. Qxg4 f5 20. Qg3 Bh8 21. c3 21. c4 !? 21... Rf7 22. Rhe1 Qc7 23. Bf4 Qd7 24. Re2 Re7 25. Rde1 Rae8 26. Be5 Kf7 27. Qf4 Bf6 28. Bc2 b5 29. Kd2 Qd8 30. Bxf5 Rxe5
31. Bxg6+? 31. Rxe5 Rxe5 (Now 31... Bg5?? is disastrous. 32. Be6+ Ke7 33. Bc8+ Kd6 34. Re6#) 32. Rxe5 Bxe5 (32... Bg5?? 33. Be6+ Ke8 34. Bc8+ and White mates.) 33. dxe5 gxf5 34. Qxf5+ Ke8 and White should win. 31...Kxg6 32. dxe5 Bg5 33. Rg2 Rf8 34. Qe3 Rf2+
35. Kd1? 35. Rxf2 Bxe3+ 36. Rxe3. White has winning chances. 35... Rxg2 36. Qd3+ Kxh6 37. Qh3+ Bh4 38. Qxg2 Bxe1 39. Kxe1 Qh4+ 40. Ke2 Qh5+ 0-1

Sunday, February 15, 2009

The First Time

Tim McGrew recounts his first try with the Blackmar-Diemer Gambit--an article taken from BDG World 75, Nov-Dec 1996.

By Tim McGrew

Most BDG'ers can remember their first tournament trial of the gambit. Ask an oldtimer for his story and you're likely to hear the exuberance of youth creep into his voice, to hear the fond and perhaps embellished recollection of that memorable occasion when he first discovered the One True Opening.
For me it's a little easier, since I'm a relative latecomer to the BDG. Having just discovered it a year or so ago when Tim Sawyer sold me some of his extra books on the gambit (thanks, Tim!), I've been enthusiastic enough to recommend it to some of my chess students.
But old habits die hard, and 1.e4 is a habit of 20 years standing with me. (It's really a trap -- so many people respond with 1...c5?!, not realizing that this puts them a move behind in the English Opening!) So despite a few postal encounters (mostly with me as Black) and some hair-raising blitz games on the Internet Chess Club, I never had a chance to try the gambit out under the strain of tournament conditions until this September, when I was suddenly confronted with an opportunity to stake everything on a gambit about which, truth to tell, I don't feel I know all that much.
2281 / Teichmann Defense Tim McGrew (2140) M. Stefanski (1900) Kalamazoo Mini Swiss, 21 Sep 1996
1. e4 d5
I sat a while thinking here -- not my normal experience on move two. On the one hand, my "official" theoretical knowledge of the BDG doesn't go all that deep. On the other hand, how could I encourage my students to take risks that I am not willing to take myself? And how would I explain to my friends Tom Purser and Tim Sawyer that I had chickened out at the last moment? No, my conscience would not permit me to bail out here!
2. d4 dxe4 3. Nc3 Nf6 4. f3 exf3
My opponent was moving crisply and with confidence, and I began to wonder whether I would regret my choice of opening. Clearly he was familiar with the theory through the next few moves.
5. Nxf3 Bg4 6. h3 Bh5 7. g4 Bg6 8. Ne5
Only here did he think for a moment. Unfortunately, this is just the point where my own theoretical knowledge begins to fade out, so from this point on it's a one-on-one game, each of us thinking it through as we go along.
8. ..e6 9. Qf3
BDG aficionados will not be surprised by this move, though it usually arises from the Gunderam move order and without h3 for White. But I had to calculate first in order to assure myself that 9...Qxd4 10.Nxg6! hxg6 11.Qxb7 really is winning.
9. ..Nd5
But this was unexpected and threw me wholly on my own resources. Obviously Black has ideas of ...Qf6 or ...Qh4+ in here, so I evolved a plan to accelerate my development. As it turns out, I was reinventing the wheel: the following maneuver was played by Diemer, Studier, and Stapelfeld in a correspondence game against Gunderam in which essentially this position arose (without the pawn on h3).
10. Bb5+! c6 11. 0–0 f6
11. ..Qf6 occurred in the aforementioned game. But there the allies were able to take advantage of the free h3 square to play Qh3! setting up a pin on the h-file and therefore threatening to devalue Black's pawn structure with a subsequent Nxg6. Since that is impossible here, White needs an alternative way to handle the position. One idea is 12. Nxd5 exd5 13. Qxd5 Qd6 14. Qxd6 Bxd6 15. Nxg6 hxg6 16. Bc4 which is at least slightly better for White because his Bishops coordinate well, e.g. 16. ..Rxh3 17. Bxf7+ Kd8 18. Bf4! Bxf4 19. Rxf4 g5 20. Re4 Kc7 21. Kg2+/-
12. Nxg6 hxg6 13. Bd3 f5
Time for another long think. Trading on f5 opens the e-file, but Black can quickly scurry away from a check there. It's more important to keep the weak pawn on e6 as a target for later attack. And the most natural way to do this involves the sacrifice of another pawn while White completes his development. Here again, Diemer had preceded me by suggesting the ensuing two moves.
13. ..Ne7 appears better at first glance because it doesn't create holes on e5 and g5. But after 14. Be3 it appears that Black has no useful way to untangle his pieces without playing ...f5 anyway.
A) 14. ..Nd7 comes to mind, but the Black Knights do not give the impression of great coordination and the central squares can be probed. 15. Bc4 Nd5 16. Rae1 Be7 17. Bg5!? is an interesting idea, striking at the weakened white squares and e6 in particular.
A1) 17. ..0–0 gives White the King's permanent address. After the temporary piece sac 18. Qe4 fxg5 19. Qxe6+ Kh8 20. Bxd5 Bf6 a plausible continuation like 21. Bb3 Bxd4+ 22. Kg2 Rf6 23. Rxf6 Nxf6 (23. ..Qxf6 24. Qxf6 gxf6 25. Rd1 Bxc3 26. Rxd7 Bxb2 27. Rxb7 may be equal or even += notwithstanding Black's extra pawn, given the active deployment of White's pieces) 24. Rd1 c5 25. Ne2 Qa5 26. Nxd4 cxd4 27. Qc4 Re8 28. Qxd4 is better for White. Black's King is safe enough, but the tripled pawns make a very bad impression and an exchange of Queens will leave Black in an almost certainly lost endgame because his King is completely locked out.;
A2) 17. ..Nxc3 18. bxc3 e5 19. dxe5 Qb6+ 20. Kg2 fxg5 21. Qf7+ Kd8 22. e6 Rf8 23. Qxg7 and White, by resolute play, has managed to generate decisive pressure -- not uncommon for a BDG!;
A3) 17. ..Qb6 is perhaps a sterner test, forcing White to sacrifice more material in a line like 18. Be3!? Qxb2 19. Nxd5 cxd5 20. Bd3 0–0–0 21. Rb1 Qc3 22. Rb3 Qa5 23. Rfb1 Nb6 24. c4 dxc4 25. Bxc4 when Black's King is more exposed than it might first appear to be.;
B) 14. ..f5 gives rise to a structure similar to the one in the game -- with the weakness at e6 in particular -- without allowing Black the solace of munching the d-pawn. 15. Rae1 Qd6 16. Qf2!? Rxh3 17. Bf4 Qd7 18. Bc4 Nd5 19. Rxe6+ (19. gxf5 Nxf4 20. Qxf4 Bd6 21. fxe6! also looks very good, but don't you want to see what happens if White just grabs the Queen?) 19. ..Qxe6 20. Re1 Qxe1+ 21. Qxe1+ Ne7 22. gxf5 gxf5 23. Kg2 Rh8 24. Be6 Rh5 (24. ..Kd8 25. Bxb8 Rxb8 26. Qe5+-) 25. Bc8 a5 26. d5 g5 27. Bxf5 gxf4 28. Bg6+ Kd8 29. Bxh5 cxd5 30. Qe6 Ra6 31. Qf7+-;
13. ..Kf7 is the other natural move. In his notes to the correspondence game mentioned above, Freidl suggests the maneuver Ne4, intending to meet Kg8 with Ng5. This looks interesting, but as the notes to this game are already long enough I will not pursue it here!
14. Bd2 Qf6
14. ..Nb4!? may actually be a better defensive try, aiming to eliminate the B/d3 before the white squares in Black's position are laid bare by exchanges on f5 or invasions on e6. 15. Rae1 Qxd4+ 16. Kg2 e5 17. gxf5
A) 17. ..Nxc2 18. Re4! (18. Bxc2? Qxd2+ 19. Re2 Qg5+ 20. Kh2 Nd7 21. fxg6 0–0–0-/+) 18. ..Qd6 19. fxg6 (19. Bxc2!? Qxd2+ 20. Rf2 Qg5+ 21. Rg4 unclear) 19. ..Be7 20. Qf7+ Kd8 21. Qxg7 Rh5 22. Qg8+ Kd7 23. Bxc2 Qxd2+ 24. Re2 Qg5+ 25. Kh2 and now the attempt to snag a perpetual by 25. ..Rxh3+ fails to 26. Kxh3 Qh4+ 27. Kg2 Qg4+ 28. Kh2 Qh4+ 29. Kg1 Bc5+ 30. Rff2! Qg3+ 31. Kf1 Qh3+ 32. Ke1 Bxf2+ 33. Rxf2 Qh1+ 34. Rf1 Qh4+ 35. Kd1 and His Majesty escapes to the Queenside;
B) 17. ..Nxd3 comes too late now since after 18. Qxd3 Qxd3 19. cxd3 gxf5 20. Rxe5+ Kd7 21. Rfxf5 White's Rooks stampede through the Black position like rogue elephants, e.g. 21. ..Bd6 22. Rf7+ Kc8 23. Re6 Bc7 24. Rxg7 Na6 25. d4 Rf8 26. Ne4! and White dominates the board
15. Rae1 Qxd4+
From this point on the game is a contribution to theory, so I have annotated it rather heavily. To forestall the natural question, no, I did not see all of this at the board! During the game I formed some general prescriptions against alternative defenses and in some cases calculated a few concrete variations. But from a practical point of view this was the right decision. The game was played at a G/90 time control, and under these conditions Black, with the onus of defense, is even more likely to falter than White is. And while a slip by White might mean only a missed opportunity, a slip by Black in the forthcoming complications would almost certainly be fatal.
16. Kg2 Kf7
16. ..Kd7 looks better, taking the K away from the open f-file, and it was the move I expected. Here again the play becomes very sharp and White must make further sacrifices in order to justify his earlier play.
A) 17. Qe2 Qf6 (17. ..Nc7 18. Bf4 Bb4 19. Be5 Qb6 20. Bxc7 Kxc7 21. Qxe6 Bxc3 22. bxc3 Nd7 23. gxf5 Rhe8 24. Qxg6+/-) 18. Ne4 Qxb2 19. Ng5 Qf6 20. Nxe6 Bd6 21. gxf5 Qh4 22. Rf3 gxf5 23. Bxf5! This sets up a very strong discovered check that Black cannot ultimately evade. 23. ..g6 24. Bg5 Qb4 25. Bg4 Qxg4+ An acknowledgment that the discovered check would be deadly. But despite the trick coming on h2, Black cannot match White's coordinated firepower and in the sequel he is simply outgunned. 26. hxg4 Rh2+ 27. Kg1 Rxe2 28. Rxe2 Na6 29. Rf7+ Kc8 30. c4 Ndc7 31. Nxc7 Nxc7 32. Be7!+-;
B) 17. gxf5 17. ..gxf5 18. Bxf5!? is another heroic approach to the position. Now a long and mostly forced variation runs 18. ..exf5 19. Qxf5+ Kc7 20. Nxd5+ cxd5 (20. ..Qxd5+ 21. Qxd5 cxd5 22. Re8! regains the piece with a better pawn structure and a nasty pin on the 8th rank: 22. ..g6 23. Rfxf8 Rxf8 24. Rxf8 b6 and now White can simplify to a winning pawn ending with 25. Bf4+ Kb7 26. Bxb8 Rxb8 27. Rxb8+ Kxb8 28. Kg3+-) 21. Bf4+! (21. Ba5+!? is less convincing, e.g. 21. ..b6 22. Re8 Nd7 23. Rxa8 bxa5 unclear) 21. ..Bd6 22. Re7+ Kc6 23. Re6 Rd8 24. Rxd6+ Rxd6 25. Qc8+ Kb6 and now after 26. Bxd6 White can escape the checks and win a piece on b8, e.g. 26. ..Qe4+ 27. Rf3 Qe2+ 28. Rf2 Qe4+ 29. Kh2 Qd4 30. Rg2 Qc4 31. Qd8+ Ka6 32. b3 Qc6 33. Bxb8+-
17. Ne4!? Be7!
Black correctly ascertains that the g5 square must, at all costs, be defended from invasion -- a point on which the fate of the game turns in just a few more moves. 17. ..Qxb2 is altogether incautious, and Black is properly punished by 18. Ng5+ Kg8 19. Rxe6 Qxa2 20. gxf5 Nd7 (20. ..gxf5 21. Qxf5 Nf6 22. Qg6+- is the prosaic win for this set of lines.) 21. fxg6 N7f6 and now White can win with the amazing and paradoxical move 22. Nh7!! , for example:
A) 22. ..Bc5 23. Qf5 (threatening 24.Rxc6!) 23. ..Bb6 (23. ..Nb4 24. Rxf6+-) 24. Qe5!+-;
B) 22. ..a6 23. Re2 b5 24. Nxf6+ gxf6 25. Qf5! and now the threat of Qe6+ forces Black to abandon f6 with 25. ..Nc7 when 26. Qxf6 is every bit as crushing as it looks;
C) 22. ..Nf4+?? looks good at first blush, but after 23. Qxf4 Qxe6 24. Nxf6+ gxf6 25. Bc4 only Black is blushing.
18. c3
18. c4!? Is a serious alternative here, banking on the exposure of Black's Queen to give White an extra tempo in the attack. At the time I rejected it because I could not find a way to break through in one subvariation, but it appears that I simply underestimated the resources at White's disposal:
A) 18. ..Nc7 19. Bc3 Qb6 20. c5! is an improved version of what might have happened in the game had Black found 19...Nc7. Here White already has his b-pawn defended and Black collapses quickly: 20. ..Bxc5 21. Ng5+ Kg8 22. gxf5 gxf5 23. Bxf5!+-;
B) 18. ..Nb4 19. Bxb4 Bxb4 20. Ng5+ Kg8 21. Rxe6 Qxb2+ 22. Rf2 Qc3 23. gxf5 Nd7 24. fxg6 Nf6 25. Ne4! In my analysis at move 18 I had missed this move, which takes care of matters very nicely. (I have assigned myself more calculation exercises as penance!) 25. ..Qc1 (25. ..Qd4 26. Nxf6+ gxf6 27. Rxf6 Rh4 28. Qf5 Bc5 29. Qe6+ Kh8 30. g7+ Kxg7 31. Rg6+ Kh8 32. Rh6+ Rxh6 33. Qxh6+ Kg8 34. Qh7#) 26. Nxf6+ gxf6 27. Qxf6 Rf8 28. Re8!+-;
C) 18. ..Nf6 let's White plant a N on the critical square with 19. Ng5+ after which the attack plays itself: 19. ..Kg8 20. gxf5 Qxb2 21. Rf2 gxf5 22. Bxf5! exf5 23. Qxf5 Rh4 24. Rxe7 Na6 25. Qg6+-
18. ..Qb6 19. c4 Nb4?!
This is the error I had anticipated. Though Black is probably objectively lost, he can put up much stiffer resistance if he is willing to hunker down and defend passively. 19. ..Nc7! is the move that makes White work hardest for the point. On the plus side, this move defends the chronic weakness at e6 that has plagued Black ever since move 13. On the minus side, it locks Black's Queen out of the action in the center and on the Kingside. The latter consideration turns out to be more important, though to prove it White must find an exact sequence of moves. After 20. Bc3 White has to solve problems of calculation against a variety of plausible defenses. This is the sort of position where one cannot hope to see everything, but the typical sacrificial themes are a guide through the labyrinth.
A) 20. ..Kg8 21. c5! Bxc5 22. Ng5 Nd5 and now
A1) 23. Bxg7!? is probably good enough to win, e.g. 23. ..Kxg7 24. Nxe6+ Kh7 25. Bxf5 (25. gxf5 Qxb2+ 26. Re2 Qa3 27. fxg6+ Kh6 28. Qg3+-) 25. ..Ne3+ 26. Rxe3 Qxb2+ 27. Re2+-;
A2) 23. Rxe6! is much crisper. Black is dead in the water after 23. ..Qd8 24. Rxg6 Bf8 25. Bxf5+-;
B) 20. ..Bf6 21. c5! (this move is critical in most lines) 21. ..fxe4 22. Bxe4 Qxc5 23. Bxf6 Kg8 24. Bxg7 Qe7 25. Bxh8 Kxh8 26. Bxg6+-;
C) 20. ..Nd7 developing the Knight and connecting Rooks looks like Black's best shot. Now White must find 21. b4! when again Black has a variety of defensive tries:
C1) 21. ..Ne8 22. c5 Qc7 23. Bc4! puts Black under a great deal of pressure, but after 23. ..Kf8 24. Bxe6 Ne5 25. Bxe5 Qxe5 26. gxf5 gxf5 White must still find 27. Nd6! in order to make full use of the open files at his disposal. Black goes under quickly after 27. ..Qb2+ 28. Re2 Qf6 29. Nxf5+-;
C2) 21. ..Qa6 22. Ng3 Qxa2+ 23. Re2 and now White crashes through with heavy sacrifices on f5 no matter where Black tries to hide, e.g. 23. ..Qb3 (23. ..Qa4 24. gxf5 gxf5 25. Nxf5 exf5 26. Qxf5+ Nf6 27. Qg6+ Kf8 28. Rxe7+-) 24. gxf5 gxf5 25. Nxf5 Bf6 26. Nd4! Qxc3 27. Bg6++-;
C3) 21. ..Bxb4 22. Rb1 c5 23. a3 Ke8 24. axb4 fxe4 25. Qxe4 e5 26. Bxe5 Nxe5 27. Qxe5+ Kd8 28. Qxg7 and Black's King is too exposed for long term survival.
20. c5!
White must sacrifice a third pawn, but the benefits are overwhelming. Black must take his Bishop away from guard duty on e7, and when White's Knight arrives on g5 all of the white squares on the kingside fall into White's hands
20. ..Bxc5
20. ..Qa5 21. a3 wins easily.
21. Ng5+ Kg8
At this point it is possible to calculate things out to mate or overwhelming material gain. There are several ways to win (22.Qe2!, for example, immediately gains a piece because of the threat of 23.Qxe6+ and 24.Qf7#), but I decided on a thematic win that involves -- finally -- the opening of all of those lines on the Kingside. Fittingly, it contains more sacrifices!
22. gxf5! Nxd3
22. ..Nd7 23. fxe6 Nf6 24. Bxg6 Nbd5 25. e7! clears the light squares for the decisive invasion 25. ..Bxe7 26. Qf5!+-
23. fxe6! Nxe1+ 24. Rxe1!
And Black resigned in view of 24...Qc7 25.Qf7+! Qxf7 26.exf7+ Kf8 27.Re8# -- a picturesque conclusion! 1–0
(This game appeared in BDG World 75.)

Friday, February 13, 2009

A little more on Durao

Yesterday's post didn't present IM Joaquin Durao in the best light. Any international master who is still going strong at the age of 79 probably has a few good games to his credit, and today I've enjoyed playing through some of Durao's games. Here's the conclusion of one that I found attractive.

J. Durao - H. Ben Rehouma, Lugano Olympiad, 1968

 After 23...Rac8? 

24. g5! Qxg5 

Black might try to run away with 24... Qe6, but White persists with 25. Qh5 h6 26. Bb3 Nc4 (26... Nbd5 27. Nxe7+ Qxe7 28. Rxc8 Rxc8 29. Bxd5 Kh8 30.Bxf7) 27. dxc4 bxc4 (27... Nxf5 28. cxb5 Qd7 29. exf5 Qxf5 30.Rxc8) 28. Bxc4 Rxc4 29. Nxe7+ Qxe7 30. Rxc4)

25. Qh5 Qxh5 26. Nxe7+ Kh8 27. Rxh5 Rc7

(27... g6 or h6 28. Nxc8 Rxc8 29. Rxe5)

28. Rxh7+ 1-0. (28...Kxh7 29. Rh1#)

Here's the complete game:

[Event "Lugano ol (Men)"]
[Site "Lugano"]
[Date "1968.??.??"]
[White "Durao, Joaquim"]
[Black "Ben Rehouma, H."]
[Result "1-0"]
[ECO "C92"]

1. e4 e5 2. Nf3 Nc6 3. Bb5 a6 4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 d6 8. c3 O-O 9. h3 Nd7 10. d3 Nb6 11. Nbd2 Na5 12. Bc2 c5 13. Nf1 Bf6 14. N3h2 Nc6 15. Ng4 Bxg4 16. hxg4 Bg5 17. Ne3 Qf6 18. g3 Ne7 19. Kg2 d5 20. Rh1 d4 21. cxd4 cxd4 22. Nf5 Bxc1 23. Rxc1 Rac8 24. g5 Qxg5 25. Qh5 Qxh5 26. Nxe7+ Kh8 27. Rxh5 Rc7 28. Rxh7+ 1-0

Thursday, February 12, 2009

Diemer - Durao, Hoogovens-B 1956

Susan Polgar has an item on her blog, 79 and still going strong, taken from a Spanish language post, about IM Joaquin Durao. Born on 25 October 1930 in Lisbon, Portugal, Durao actually won't be 79 for a few more months, but the point is that he's still active at an advanced age. According to Jeremy Gaige's Chess Personalia, he was awarded the international master title in 1975. Although his rating has gradually fallen to the low 2100s, in the mid 1970s, when Durao was in his forties, it stood around 2350. In 1956 Durao played in the Hoogovens-B tournament in Beverwijk. This was the lower master group of what is now the very strong Corus tournament, the latest interation just concluded a couple of weeks ago. Today the tournament is strong indeed, with a C group added. The players in all three groups, except for several IMs in C, I believe, were grandmasters. In 1956 things were much different--but again, grandmasters did not litter the chess landscape then as they do today. Nor did players have computer assistants in those days. In 1956 Diemer also played in Group B in Beverwijk. In fact he won it, with a score of 6.5 out of 9, a half point ahead of his nearest rival. Here's his short little game with Durao from the sixth round:

E. J. Diemer - J. Durao Hoogovens-B, Beverwijk, 1956 Hübsch Gambit

1. d4 Nf6 2. Nc3 d5 3. e4 Nxe4 4. Nxe4 dxe4 5. Bf4
Preparing to play f3 (what else?), but first he needed to hold back e5. 5...Nd7 6. f3 exf3 7. Nxf3 Nf6 8. Bc4 e6 9. O-O Be7 10. Qe1 O-O 11. Bd3 Nd5 12. Be5 Bf6 13. c4 Bxe5
14. dxe5 Nf4 15. Bc2 Qe7 16. Qe3 Ng6 17. Ng5 h6?
17... f5 was needed. 18. Nxf7 Rxf7 19. Bxg6 Rxf1+ 20. Rxf1 Bd7 21. Rf7 Qd8 22. Qf3 1-0.  
Black resigned, as there was no way to meet 23.Rxg7+ Kxg7 24.Qf7+ Kh8 25.Qh7#; if 22...Qe8 23. Qxb7 Rc8 24. Rxg7+ Kxg7 25. Bxe8 Rxe8 26. Qxc7 wins.

Sunday, February 8, 2009

A non-routine Bishop sacrifice on h6

In yesterday's post I looked at a "routine Bishop sacrifice on h6." Today's post looks at a less than routine Bishop sacrifice on h6. Almost ten years ago Macon Shibut, editor of Virginia Chess, published an article on the BDG that won a Chess Journalist of America award.The following excerpt is from that article, "What's the Deal with the BDG?," which originally appeared in Virginia Chess, Number 3, 1999, and was republished with permission of the editor and author, Macon Shibut. "My overall assessment is that the Blackmar-Diemer is: a useful situational weapon -- perhaps too speculative as the centerpiece of one's repertoire, but White does get an active, attacking game and definite practical compensation. And an unprepared Black may easily get fried. My observation of the Gemeinde's general level notwithstanding, there are some wonderful players who specialize in this gambit and they've produced some truly remarkable games and analyses. Charles Diebert (2315) - John Burke (2185) US Amateur Team Midwest 1987 Blackmar-Diemer Gambit, Euwe Defense 1 d4 Nf6 2 Nc3 d5 3 e4 dxe4 4 f3 exf3 5 Nxf3 e6 6 Bg5 Be7 7 Bd3 Nbd7 (7...0-0 8 0-0 Nc6 9 Qe1 Nd5 10 Bxh7+ Kxh7 11 Qh4+ Kg6 12 Bxe7 Qxe7 13 Qg4+ Kh6 14 Qh3+ Kg6 15 Nh4+ 1-0 Purser-Casteel, corr 1982, was another typical BDG denouement) 8 0-0 h6!? 9 Bf4 c6 10 Kh1 0-0 11 Qd2 Re8 12 Bxh6
This may look premature to the uninitiated, but on Planet Diemer such sacrifices are routine. White's immediate threats don't amount to much, but his initiative proves to have surprising endurance. 12...gxh6 13 Qxh6 Bf8 14 Qh4 Bg7 15 Ne5
(Calmly wheeling pieces into assault position. Yes, this is the BDG way: first sacrifice, then prepare the attack. At any rate, White didn't have to fear defense by exchange here: if 15...Nxe5 16 dxe5 Nd7 the end would have been 17 Qh7+ Kf8 18 Rxf7+ Kxf7 19 Bg6+ Kf8 20 Rf1+) 15...Qe7 16 Rf3 Nf8 17 Rh3
(Menacing for sure, but note: for the present at least, there is no threat.) 17...c5 18 Rf1 cxd4 19 Rff3!
White's exaggerated nonchalance is delightful. Material be damned, he's got a plan and he's sticking to it. The fact that Black ultimately fails to stem the attack despite his two extra pieces and a half dozen moves to brace himself creates the impression that the whole thing may well have been sound! 19...dxc3 20 Rfg3
(At last a threat! . Qh8 mate. And it draws blood.) 20...Ng6 21 Bxg6 Qd6 22 Bd3 Kf8 23 Qg5
Now if 23...cxb2 24 Qxg7+ Ke7 25 Qxf7+ Kd8 26 Qxf6+ Kc7 27 Rh7+ Kb8 (or 27...Bd7 28 Rxd7+ Qxd7 29 Nxd7 b1Q+ 30 Bf1 Kxd7 31 Rg7+ Kc6 32 Qc3+ winning) 28 Nc6+! bxc6 (28...Qxc6 29 Qe5+) 29 Qxb2+ [Diebert] Great stuff! 23...Ng4 24 Ng6+!
24...fxg6 25 Rf3+ Bf6 26 Rxf6+ Ke7 27 Rh7+ Kd8 28 Rf8+ 1-0
Who wouldn't want to play such a masterpiece?

Friday, February 6, 2009

A routine Bishop sacrifice on h6

In a BDG that showed up in TWIC recently White missed a fairly routine Bishop sac on an imprudently advanced h-pawn.

The game went 1. d4 d5 2. e4 dxe4 3. Nc3 Nf6 4. f3 exf3 5. Nxf3 c6 6. Bc4 e6 7. O-O Be7 8. Bg5 O-O 9. Qe1 b5 10. Bd3 Nbd7 11. Qh4 h6?

  After 11...h6?

Here White played 12. Bxf6 and the game was drawn after sixty moves. You can clip the PGN at the end of this post and play through the game if you'd like. But the point is that this position cried out for the Bishop sac on the h-pawn. After 12.Bxh6 Black's best defense is probably 12...g6, giving up the exchange, although White may find something better than that. But if Black accepts the sac?

12.Bxh6 gxh6 13.Qxh6

 After 13.Qxh6

 This is one of those positions where you don't have to calculate every possibility. If you play the BDG you've seen it or a close relative dozens of times. As long as White has the bishop on d3, the knight that can go to g5 and the rook on the half open f-file that can sac on f6 or double with the rook from a1 or get to the g or h- files, a successful Black defense is highly unlikely.

13...Re8 Not the best, but often tried. 14. Ng5 Nf8  (This doubles the guard on h7, opening a line to White's d-pawn while still guarding against an immediate sac on f6. (14... Bf8?? 15. Bh7+ Kh8 16. Nxf7# happens now and then in blitz.) 15. Ne2 and 16. Rf4

 After 15.Ne2

13...e5 14. Ng5 Qb6 15. Bh7+ (Gaining a tempo to get the Bishop in position to remove the Knight on d7) Kh8 16. Bf5+ Kg8 17. Bxd7 Qxd4+ 18. Kh1 Qxd7 19. Rxf6

After 19.Rxf6

13...Qb6 14.Ng5 Qxd4+ 15.Kh1 and Black has no good continuation.

After 15.Kh1

It's been said before: in a gambit you have to tolerate a little uncertainty. But in this position it's very little.
Here's the full game:

[Event "ch-Nassau"]
[Site "Mineola USA"]
[Date "2008.12.08"]
[Round "8"]
[White "Mennella, James"]
[Black "Kan, Andrew"]
[Result "1/2-1/2"]

1. d4 d5 2. e4 dxe4 3. Nc3 Nf6 4. f3 exf3 5. Nxf3 c6 6. Bc4 e6 7. O-O Be7 8. Bg5 O-O 9. Qe1 b5 10. Bd3 Nbd7 11. Qh4 h6 12. Bxf6 Nxf6 13. Ne5 Bb7 14. Rad1 b4 15. Ne2 Qc7 16. Rde1 c5 17. c3 bxc3 18. bxc3 Qd6 19. Rb1 Rab8 20. Qf4 Qd5 21. Qg3 Ne4 22. Bxe4 Qxe4 23. Nd7 Bh4 24. Qh3 Qxe2 25. Nxf8 Kxf8 26. Rxb7 Rxb7 27. Qxh4 Qe3+ 28. Kh1 Re7 29. dxc5 Qxc5 30. Qg3 Qc4 31. Rb1 Rb7 32. Qd6+ Kg8 33. Rc1 Qxa2 34. Qd8+ Kh7 35. Qd3+ g6 36. h4 Qf2 37. Qe4 Rb2 38. h5 Qf5 39. hxg6+ Qxg6 40. Qf3 a5 41. Rf1 Rb1 42. Rxb1 Qxb1+ 43. Kh2 Qb8+ 44. Kh1 Qa7 45. Qe4+ Kg7 46. Qe5+ Kg8 47. Qg3+ Kh7 48. Qd3+ Kg7 49. Qg3+ Kf8 50. Qd6+ Ke8 51. Qc6+ Qd7 52. Qa8+ Qd8 53. Qc6+ Kf8 54. c4 Qd1+ 55. Kh2 a4 56. c5 Qd4 57. Qa8+ Kg7 58. c6 Qh4+ 59. Kg1 Qe1+ 60. Kh2 Qh4+ 1/2-1/2

Tuesday, February 3, 2009

More on Bogoljubov

This morning I was trying to declutter my office (aka, my bedroom) a bit, removing books from a table in search of its surface, when I picked up a copy of Chess Sacrifices and Traps by Alfred Emery, a little book of 118 pages first published in England in 1924. My copy is a fifth edition, 1937, which I found on eBay a couple of years ago. Unfortunately, I have a hard time picking up a book without also wanting to browse through it. In a section of the book on "Middle-Game Sacrifices" I once again came across the game Bogoljubov-Mieses from the great 1925 Baden-Baden tournament. Alekhine won it without losing a game, ahead of Rubenstein, Saemisch, and Bogoljubov, who came in fourth ahead of seventeen others, including such greats as Tartakower, Marshall, Gruenfeld, Nimzowitch, Reti, Spielmann, Tarrasch. Here's the game: Bogoljubov,Efim - Mieses,Jacques Baden-Baden, 1925 Dutch Defense 1.d4 f5 2.g3 Nf6 3.Bg2 e6 4.Nf3 d5 5.0-0 Bd6 6.c4 c6 7.Nc3 Nbd7 8.Qc2 Ne4 9.Kh1 Qf6 10.Bf4 Bxf4 11.gxf4 Qh6 12.e3 Ndf6 13.Ne5 Nd7 14.Rg1 Nxe5 15.dxe5 Nxc3 16.bxc3 Bd7 17.Rad1 b5 18.Qb2 0-0 19.Qa3 Rfd8 20.cxb5 cxb5 21.Qa6 Qh5
22.Bxd5! exd5 23.Rxg7+ Kxg7 24.Qf6+ Kg8 25.Rg1+ Qg4 26.Rxg4+ fxg4 27.f5
How far ahead does a master see? Since this line is almost forced once the sac is accepted I think Bogoljubov must have seen to this point, knowing he would at worst have the connected passed pawns and his King relatively secure. 27...Rdc8 28.e6 Bc6 29.Qf7+ Kh8 30.f6 Rg8 31.Qc7 Rac8 32.Qe5 d4+ 33.Kg1 Bd5 34.f7+ Rg7 35.Qxd5 1-0
"Countless masterpieces of play remain to assure him the immortality he sought," wrote Diemer.

Sunday, February 1, 2009

Diemer on Bogoljubov

E. J. Diemer knew GM Efim Bogoljubov quite well, having become acquainted with him, I believe, during his 1934 world championship match with Alekhine in Baden Baden. An entry in Edward Winter's Chess Notes reprints a tribute by Diemer which was published on page 221 of the August 1952 CHESS after Bogoljubov's death:
"The last time I saw him was in Freiburg, ten days before his death. On 6 June he won a lightning-chess tournament organized among the members of the Freiburg team, for whom he had played at top board since 1950. The next day, he helped Freiburg beat another local team by 8:0 and the same evening he beat the well-known Berlin master Mross (in the last tournament game of his life) to help Freiburg register a 4½-3½ win against a team (Berlin-Eckbauer) which had successfully defeated Luxembourg, Cologne, Basle and Lucerne. I had a conversation with him then of rare seriousness. As if conscious of the nearness of his end, he spoke, on this last occasion, about – Chess Immortality. I discovered at this late hour in his life, and I pass it on as his closing thought, that Bogoljubow wanted his chess to be regarded as an art and himself as an artist. He feared, he said, that not one of his games, even from the great tournament at Moscow in 1925, the zenith of his career, would be deemed worthy of inscription in the scrolls of immortality. So high did he set his ideals. And so sceptically did he look back over his 40 years of masterly endeavor. Luckily the chess world will not share his pessimism. Countless masterpieces of play remain to assure him the immortality he sought."