Steinitz exchange lemma

Alexander Anatolyevich Motylev – 侯逸凡 (Hóu Yìfán)
47th International Chess Festival “In Memoriam Hans Suri”; Biel/Bienne, July 18, 2014
Sicilian Defence B48

1. e4 c5 2. Nf3 e6 3. d4 cxd4 4. Nxd4 Nc6 5. Nc3 Qc7 6. Be3 a6 7. Qd2 Nf6 8. 0-0-0 Be7 9. f3 b5 10. g4 Nxd4 11. Bxd4 Bb7 12. g5 Nh5 13. Be5 Qxe5 14. Qxd7+ Kf8 15. Qxb7 Bxg5+. Another try is 15. ... Qb8 16. Rd7 Qxb7 17. Rxb7 g6 18. a4 b4 19. Na2 Bxg5+ 20. Kb1 a5 21. Bc4 Nf4 22. Rd1 Rd8 23. Rxd8+ Bxd8 24. Nc1 h5 25. Nd3 Nxd3 26. cxd3 g5 27. d4 g4 28. Be2 Bf6 29. e5 Bh4 30. fxg4 hxg4 31. Rb8+ Kg7 32. Rxh8 Kxh8 33. Bxg4 Bf2 34. d5 exd5 35. e6 fxe6 36. Bxe6 d4 37. Kc2 Kg7 38. Kd3 Kf6 39. Bg4 Ke5 40. b3 Bh4 41. h3 ½ : ½ Khairullin – Jumabayev, Moscow 2014. 16. Kb1 Qb8 17. Rd7 Qxb7 18. Rxb7 Bf6 19. a4 Bxc3 20. bxc3 bxa4

21. Bc4. “Theory” contemplates 21. Bxa6 g5 22. Bb5 Kg7 23. Rd1 Rhb8 24. Rxb8 Rxb8 25. c4 Nf4 26. Kb2 Ng6 27. Ka3 Ne5 28. Kxa4 Nxf3 29. c5 Ne5 30. c6 Rc8 31. Rd6 Kf6 32. Kb4 g4 33. Kc5 Ke7 34. Rd1 h5 35. Kb6 Rb8+ 36. Kc5 Rc8 37. Kb6 Rb8+ 38. Ka6 Nxc6 39. Bxc6 Rb2 40. Ba4 Rb4 41. Bb5 Rxe4 42. Rc1 h4 43. c4 Re2 44. c5 Rxh2 45. c6 Rd2 46. c7 Rd8 47. cxd8=Q+ Kxd8 48. Be2 f5 49. Rc4 Kd7 50. Bxg4 fxg4 51. Rxg4 Kc6 52. Ka5 Kd5 1 : 0 Ter-Sahakyan – J. Polgár, Yerevan 2014. 21. ... g6 22. Rd1 Rc8 23. Ba2. On 23. Bxa6 Rxc3 24. Rdd7 Rxf3 25. Bc4 Kg7 26. Bxe6 Rf8 with roughly even play. 23. ... Rg8 24. Rd6 g5 25. Rxa6 Rg6 26. Raa7 Rf6 27. e5. If 27. Bxe6 then 27. ... Rxe6! 28. Rxf7+ Kg8 29. Rxh7 Ra6! with equality. 27. ... Rxf3 28. Bxe6 Rf1+ 29. Ka2 fxe6 30. Rxh7 Kg8 31. Rxh5 Rf5 32. Rxa4 Rxc3 33. Rg4 Rxc2+ 34. Kb3 Re2 35. Rgxg5+ Rxg5 36. Rxg5+ 36. Rxg5+ Kh7 37. h4 Re4 38. h5 Kh6 39. Rg6+ Kxh5 40. Rxe6 Kg5 41. Re8 ½ : ½. A fierce defence by Miss 侯逸凡 (Hóu Yìfán).

Alexander Anatolyevich Motylev vs. 侯逸凡 (Hóu Yìfán)
Biel/Bienne, July 18, 2014
Photo: bielchessfestival.ch