Check and Mate

侯逸凡 (Hóu Yìfán) – 张岚琳 (Zhāng Lánlín)

17th Chinese Chess League Division A Regular-Rapid “武陵山大裂谷杯” (“Wǔlíng Mountain Great Rift Valley Cup”); time control: 25 minutes plus 10 seconds per move; 重庆 (Chóngqìng), September 8, 2022

Sicilian Defence B53

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Qxd4 e5 5. Bb5+. Or 5. Qd1 h6 6. Bc4 Nf6 7. Nc3 Be6 8. Bb3 Be7 9. 0-0 0-0 10. Be3 Nc6 11. Qe2 Na5 12. Rfd1 Qc7 13. Nd5 Nxd5 14. Bxd5 Nc4 15. c3 Rac8 16. Rac1 a6 (16. ... Qa5!=) 17. b3 Nxe3 18. Qxe3⩲ 侯逸凡 (Hóu Yìfán) – Nakamura, 16th Unive Chess Tournament, Hoogeveen 2012.
5. ... Nc6 6. Qd3 h6 7. c4 Nf6 8. Nc3 a6 9. Bxc6+ bxc6 10. 0-0 Qc7 11. Rd1 (11. b3 Be7 12. Bb2 Be6 13. Rac1 0-0 14. Nd5 cxd5 15. cxd5 Qb7 16. dxe6 Qxe4 17. exf7+ Rxf7 18. Qxe4 Nxe4 19. Rfd1 Nxf2 20. Kxf2 e4 21. Rc4 exf3 22. gxf3 Rf5 23. Rg1 Bf8 24. Rc7 Rc5 25. Rxc5 dxc5 26. Rg4 Kf7 27. Re4 Rd8 28. Ke2 Re8 29. Be5 Re6 30. Kd3 Bd6 31. Rf4+ Ke7 32. Bxd6+ Rxd6+ 33. Ke3 Re6+ 34. Kf2 Rd6 35. Ra4 Ke6 36. Ra5 Rc6 37. Ke3 Kd5 38. b4 Kc4 39. Rxc5+ Rxc5 40. bxc5 Kxc5 41. Ke4 h5 42. h4 a5 ½ : ½ Vasiukov – Kavalek, 9th IBM international Chess Tournament, Amsterdam 1969)
11. ... Be7 12. b3 0-0 13. Ba3 Qa5 14. Na4 Rd8 15. Qe3 c5 16. Bb2 Bd7 17. Nc3 Qc7 18. Nh4 Rdb8? (⌓ 18. ... Qc8 Δ 19. Qd3 g6)
19. Nf5 Bxf5 (19. ... Bf8 20. Qg3 Kh8 21. Qh4→)
20. exf5 Re8 21. Re1 Rad8 22. Rad1 Bf8 23. h3 Qc8 24. Qd3 Re7 25. Qc2 Red7 26. Na4 Qc6 27. f4

27. ... Nh5? Losing a pawn without any compensation. 27. ... Be7 was better, so as to reply to 28. fxe5 dxe5 29. Rxd7 with 29. ... Nxd7 holding everything together. That being said, there are founded reasons to suppose that White would have preferred 28. Nc3 followed by Nc3-d5 maintaining a conspicuous advantage.
28. fxe5 dxe5 29. Rxd7 Rxd7 30. Bxe5 Be7 31. Nc3 Bh4 32. Re4 Bg5 33. Nd5 Nf6 34. Bxf6 Bxf6 35. Re8+ Kh7

36. Qe4 a5? There is very little doubt that 36. ... Qd6 37. Re6! Bd4+ 38. Kh1 fxe6 39. fxe6+ Kh8 40. exd7 Qxd7 41. Ne7! was also enough of an advantage for 侯逸凡 (Hóu Yìfán) to squeeze out a win.
37. Kh1. Of course White could play 37. Re6! at once.
37. ... a4 38. Re6! Qb7. 38. ... fxe6?? would cost the Queen after 39. Nxf6+.
39. Rb6 Qa7

40. Rxf6! axb3. If 40. ... gxf6 then 41. Nxf6+ Kg7 42. Nxd7 Qxd7 43. Qe5+ followed by Qe5xc5 with an easily won ending.
41. Rxh6+! gxh6 (41. ... Kxh6 42. Qh4#)
42. f6+ Kh8 (42. ... Kg8 43. Qg4+ Kf8 44. Qg7+ Ke8 45. Qg8#)
43. Qg4 1 : 0. Mate follows on g7.