Gate to the East

Vladimir Konstantinovich Bagirov – Roberto Cosulich
International Tournament; Naples, December 1977
Nimzo-Indian Defence E30

1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Bg5. The Leningrad Variation, so named because it was in great favour among the players from that city, including also 10th World Chess Champion Boris Vasilievich Spassky.
4. ... h6 5. Bh4 c5 6. d5 Bxc3+ 7. bxc3 d6 8. Nf3 e5. Wikipedia’s popular assessment is open to question: “Black has achieved a Hübner Variation-like blockade, the difference being that White’s dark-squared Bishop is outside the Pawn chain. The pin on the f6-Knight is very annoying, and Black often breaks it by playing the drastic ... g7-g5, which also clamps down on a potential f2-f4 break by White. This move weakens Black’s Kingside, so rather than castle on that side, Black usually safeguards the King by playing ... Ke8-d8-c7”.
9. Nd2 Nbd7 10. e3 Nf8 11. Bd3 Qe7. If 11. ... Ng6 then 12. Bg3 0-0 13. 0-0 Ne7 14. f4! exf4 15. Rxf4 Ng6 16. Rxf6!? Qxf6 17. Ne4 Qd8 18. Nxd6 with enough compensation for the Exchange, Spassky – B. Larsen, USSR vs. Rest of the World, Belgrade 1970.

12. Qb1!? Quite a good idea — even though, years later, White would prefer to play 12. Bxf6! Qxf6 13. 0-0 Qe7! 14. Qc2 Nd7 15. f4 Nf6 16. Rae1 0-0 17. f5 a6 18. Ne4⩲ with a slight edge, Timman – Romanishin, 9th Interpolis Chess Tournament, Tilburg 1985.
12. ... g5 13. Bg3 Rg8 14. Bf5 Ng6 15. a4 Nh5 16. h3?! An unnecessary weakening of the Kingside. White ought either to exchange or retreat his light-squared Bishop, after which the Black King would have to decide whether to go West (... Ke8-d8-c7), or East (... Ke8-f8-g7-h8), with complex play and reciprocal chances in both cases.
16. ... Bxf5 17. Qxf5 Ng7 18. Qb1 f5 19. f3 0-0-0 20. Bf2 Rdf8 21. a5

The rush is on.
21. ... e4! A brilliant positional Pawn sacrifice which vacates the e5-square for the g6-Knight in preparation for a future attack.
22. fxe4 Ne5 23. 0-0? Castling into it. After this mistake, Black’s attack grows irresistible. 23. exf5! still offered White the means to escape the worst: a) 23. ... Nxf5 24. g4 Nf3+! 25. Ke2 (25. Nxf3? Nxe3! would be very bad for White) 25. ... N5d4+! 26. cxd4 Nxd2 27. Qd3 Ne4 (very harsh balanced); or b) 23. ... g4!? (who knows, maybe Cosulich would have played like this) 24. e4 Nxf5! 25. a6! b6 26. exf5 Nd3++ 27. Kf1 Nxf2 28. Kxf2 g3+ 29. Kf3 Qe5 30. Ne4 Rxf5+ 31. K~ Re8 regaining the piece with an easier game to play.

23. ... g4! 24. h4. 24. hxg4 is also answered by 24. ... Nh5! 25. gxh5 Qg5 26. g3 f4! 27. exf4 Rxf4 with a vehement attack.
24. ... Nh5. Threatening ... g4-g3 followed by ... Qe7xh4.
25. a6 b6 26. Be1. Not 26. g3 on account of 26. ... Nf3+ 27. Nxf3 gxf3 28. Kh2 Nxg3! 29. Bxg3 Rxg3! 30. Kxg3 Qg7+ 31. Kxf3 fxe4+ 32. Ke2 (if 32. Kxe4 then 32. ... Qg6+ followed by mate) 32. ... Qg2+ with mate in two.
26. ... g3 27. Rxf5 Qxh4 28. Nf1. White to play and selfmate in three moves: 28. Rxf8+?? Rxf8 29. Nf1? Qh1+! 30. Kxh1 Rxf1#. However, Bagirov can do little or nothing to prevent the final attack.
28. ... Rxf5 29. exf5 Nf6! The bells toll for His Majesty as Black is threatening ... Nf6-e4-f2.
30. Nxg3 Kc7! No illusion is left.
31. Qc2 Nfg4 32. Qe4 Qh2+ 33. Kf1 h5! 34. Ke2 Nf6 35. Qf4 h4 36. Ne4 Qxg2+ 37. Nf2 Rg4 38. Qh6 Ne4 39. Qh7+ Rg7 40. Qxg7+. Desperation, but 40. Qxh4 Qf3+ 41. Kf1 Ng3+ leads to mate in a few moves.
40. ... Qxg7 41. Nxe4 Qg4+ 0–1.