Thomas Erben (1840) - Jyrki Heikkinen (1880)

Diemer-Duhm Gambit, DDGA'96, 1.4.1997

1. e4 e6 2. d4 d5 3. c4 dxe4 4. Nc3 Nf6 5. f3 Bb4 6. Be3 Nc6

6... c5 7. a3 Bxc3+ 8. bxc3 Qa5 -/+ or 7. dxc5 Bxc3+ 8. bxc3 Qa5 =/+.

7. Qc2

7. fxe4 Nxe4 8. Qg4? Nxc3 9. a3 Nd5+ 10. axb4 Nxe3 -+.

7... O-O 8. O-O-O exf3 9. Nxf3 h6 10. h3 Bxc3 11. Qxc3 Qe7

I dropped the plan I had with 10... Bxc3: 11... Ne4 12. Qe1 f5 13. Bd3 seemed to simply threat 14. Bxe4.

12. Bd3 Rd8

Something is wrong with Black's last four moves, but what? White has a clear space advantage, which is even strengthened with the next move. One serious threat is 13. Qd2 and 14. Bxh6! +/-.

• 12... b5!? 13. cxb5 Nb4 14. Qc5! (14. Bb1) Qxc5 15. dxc5 Nxa2+ 16. Kb1 Nb4 17. Bc4.
• 12... Nb4 13. Bb1 Ne4 14. Qe1 but what then?

13. g4

White's space advantage looks decisive.

13... b5 14. g5 Nb4?

What a blunder. Of course, 14... hxg5 15. Bxg5 does not look very tempting, either.

15. gxf6 Nxa2+ 16. Kd2

Oops. When I played 14... Nb4, I had only seen a very stupid line 16. Kc2 Qxf6 17. Qb3 Qxf3 18. Qxa2?? Qxe3 -+.

16... Qxf6 17. Qb3

17. Qa3 Qxf3 18. Qe7!? Qg2+ 19. Be2 threatening Bxh6.

17... Qxf3

17... bxc4 18. Qxc4 Ba6?! (18... Qxf3) 19. Qxa6 Nb4 20. Qb7 +/-.

18. Qxa2

Erben: I felt very uncomfortable. The queen is totally out of play on a2, and I think Black would reach a better position by developing pieces (Bc8 and Ra8) and beginning attack in the center afterwards.

18. Rdf1 Nc1!? but not 18. cxb5? Qg2+ 19. Be2 e5 20. Rdg1 Nc1! =/+.

18... e5

Suddenly, I was happy with the position. I had an idea to exchange b- and c-pawns to White's c- and d-pawns, play Rac8 and Bb7 or Ba6 -- and attack. It also looked like Black could create a passed f-pawn.

19. d5

19. dxe5?? Rxd3+ 20. Kxd3 Bf5+ 21. Kc3 Qxe3+ 22. Kb4 a5+ -+ or 19. cxb5? exd4 -/+.

19... c6

• 19... bxc4 20. Qxc4 (20. Bxc4 Bxh3 -/+) Qxd5 (20... Bxh3? 21. Be4! Qh5 22. Bg2 +-) 21. Qxd5 Rxd5 22. Ke2 +/=.
• 19... e4 20. Be2 Qg3.
• 19... Bxh3? 20. Be2 Qg3 21. Rdg1 Qh4 (21... Bg2 22. Bf1) 22. Rg4 +-.

20. Rdg1

20. Qa5 Bxh3 21. Be2 Qe2 22. Rxh3 bxc4 is unclear with two bishops against six pawns!

20... Kh8

• 20... bxc4 21. Qxc4 Qxd5 (21... cxd5 22. Qh4 Bf5 23. Rxg7+! Kxg7 24. Qxh6+ Kg8 25. Rg1+ Bg6 26. Bxg6 +-) 22. Qxd5 Rxd5 (22... cxd5 23. Bxh6 +/-) 23. Ke2 Rb8 +/-.
• 20... g5!? 21. h4 +/-.
• 20... Bf5 21. Rf1 Qg2+.
• 20... h5 21. Bh6 g6 22. Bxg6? fxg6 23. Rxg6+ Kh7 24. Rhg1 Bg4! -/+.

21. Rh2 f5

21... bxc4 22. Qxc4 Qxd5 23. Qxd5 Rxd5 24. Rhg2 d4 (24... g5 25. Bxg5! +-) 25. Rxg7!? dxe3+ 26. Kxe3 f5 27. R7g6 Kh7 28. Bc4 Bd7 29. Rg7+ Kh8 30. R7g6 =. However, White must have something better than 25. Rxg7.

22. Qa5!

Erben: After early c6 and f5, the queen returns to the game and creates immediate threats.

Nos Black is doomed to retreat. I was hoping for something less deadly:

• 22. Rhg2 f4 23. Bc5 (23. Rxg7?! Qxe3+ 24. Kc2 e4 25. Qa5?! Qxd3+ 26. Kc1 Bf5 27. Qc7 Qxc4+ -+) e4 24. Be2 (24. Bc2 g5! -/+) e3+ 25. Kd1 Qe4.
• 22. Rf2 Qxh3 23. Qa5 Bd7 24. dxc6?? (24. Rfg2) f4 -/+.

22... Rg8

• 22... Bd7 23. Qc7 f4 24. Bc5 e4 (24... bxc4 25. Bxc4 +-) 25. Be2 (25. Bc2!) e3+ 26. Kc1 Qe4 27. dxc6 Rac8 +/- (27... Qxc6!?).
• 22... Rd7? 23. Rf2 Qh5 24. Bxf5 Re7 (24... Rd6 25. Qc7 +-) 25. Bg6 +-.

23. Rf2

23. Qc7 f4 24. Bc5

• 24... e4 25. Bc2! cxd5 26. Rhg2 e3+ 27. Kc1 e2 28. Rxg7!! Qf1+ 29. Rxf1 exf1Q+ 30. Kd2 +-.
• 24... cxd5? 25. Rxg7! Rxg7 26. Qd8+ Rg8 27. Qf6+ Rg7 28. Qf8+ Rg8 29. Qxh6#.

23... Qxh3 24. Qc7 f4

There were only bad alternatives:

• 24... bxc4? 25. Qxe5 cxd3 26. Bd4 +-.
• 24... e4? 25. Rh2 Qf3 26. Be2 (or 26. Qe5) +-.
• 24... g5? 25. Qxe5+ Kh7 (25... Rg7 26. Bd4) 26. Rxf5 +-.

25. Bxf4

A) 25. Rxf4! wins immediately

• 25... exf4 26. Bd4 Bd7 (26... Qd7 27. Qxf4) 27. dxc6 Rc8 28. cxd7 Rxc7 29. Bxg7+ mates.
• 25... Qd7 26. Qxe5 Re8 (26... bxc4 27. Rh4) 27. Rf6!! Kg8 28. Rxg7+! mates.
• 25... Qh5 26. Qxg7+! mates.

B) 25. Rxg7?!

• 25... Rxg7! 26. Qd8+ Rg8 27. Qf6+ Rg7 28. Rxf4 (28. Qf8+ with perpetual check, but the best may be 28. Bc5!?) exf4 29. Bd4 Qg2+ and 30... Bh3 is probably a draw.
• 25... Qxe3+ 26. Kc2 Qxd3+ (26... Qxf2+ 27. Kb3 bxc4+ 28. Ka2 +-) 27. Kxd3 Bf5+ and 28... Rxg7 +/=.
• 25... fxe3+ 26. Kc2 +-.

25... bxc4

25... exf4 26. Qxf4 (Erben: I thought 26. Rxg7 to end in a draw) Qd7 27. Qe4 g5 28. Qe5+ Qg7 29. Rf6! or 29. Rf7 +-.

26. Bf1 Qh4

26... Qd7 27. Qxd7 Bxd7 28. dxc6 Bxc6 29. Bxe5 threatening Rf7 +/-.

27. Be3 Qe4

27... cxd5 28. Rf8! +-.

28. Bxh6

• 28. Rf8 g5 29. Bxg5 also wins easily.
• 28. Qxc6 Bb7!? 29. Qxb7 (29. Qxc4 simply wins) Rab8 30. Qxa7 Rxb2+ 31. Kd1 c3! 32. Bc1 (32. Qc5 Rb1+ 33. Bc1 Qa4+ 34. Rc2 Rxc1+! 35. Kxc1 Qa1#) c2+ 33. Kd2 Qxd5+ 34. Ke3 (34. Bd3 Rb3) Rb3+ mates.

28... Qxd5+

28... gxh6 29. Rxg8+ mates.

29. Kc1 gxh6

29... Bg4?! 30. Bd2 (or 30. Rd2) Bh5 31. Rh2 g6 32. Rxg6! +-.

30. Rxg8+ 1-0

The last hope was 30. Rf8?? Bg4! and Black would probably win. After the text move, everything is clear:

• 30... Qxg8 31. Qxe5+ Qg7 (31... Kh7 32. Qf7+) 32. Rf8+ Kh7 33. Qe4+ mates.
• 30... Kxg8 31. Rg2+ Kf8 32. Qg7+ Ke8 33. Qh8+ Ke7 34. Rg7+ +-.

PGN version.