Combinatorics

Alexandra Konstantinovna Kosteniuk – 侯逸凡 (Hóu Yìfán)

4th Online Women’s Speed Chess Championship Main Event; Quarterfinal match game 4; time control: 5 minutes plus 1 second per move; chess.com, July 28, 2022

Sicilian Defence B53

1. e4 c5 2. Nf3 d6 3. d4 cxd4 4. Qxd4 Nc6 5. Bb5 Bd7 6. Qd3 Nf6 7. Bg5 e6 8. Nc3 Be7 9. 0-0-0 a6 10. Bxc6 Bxc6 11. Nd4 Qa5?! Sounder seems 12. ... Rc8 12. f4 h6 13. Bh4 (13. Qh3!? 0-0 14. Bxh6 Bxe4∞) 13. ... 0-0 14. f5 Ng4 with approximately even chances, Gipslis – Kupreichik, 15th Sportland NRW Cup, Senden 1999.
12. Bxf6 gxf6 13. f4 Bd7 14. f5 0-0-0 15. Qh3. Later on Kosteniuk preferred 15. Qc4+ Qc5 16. Qb3 Qe5 17. g3 which, indeed, seems more promising for White, Kosteniuk – 侯逸凡 (Hóu Yìfán), 4th Online Women’s Speed Chess Championship Main Event, chess.com, July 28, 2022, Quarterfinal match game 10 (time control: 3 minutes plus 1 second per move).
15. ... Kb8 16. Kb1 Qe5 17. Rhe1 h5 18. g3 Qc5

19. Nce2? Kosteniuk goes astray in her convoluted logistics. Instead she should have consolidated by 19. Rd3! maintaining her positional edge.
19. ... Rc8 20. c3 e5 21. Nc2 Bc6 22. Nc1? Allowing Black’s advance is very unadvisable. White ought first to have played 22. Qg2 — and only then follow up with Ne2-c1.

22. ... d5! 23. Nd3 Qa5 24. Ndb4? It’s impressive how quickly White’s situation deteriorated. Paraphrasing Bobby Fischer, add another to those melancholy case histories entitled “the wrong Knight”.
24. ... d4 25. Nxc6+ Rxc6 26. cxd4? As they say, mistakes never come alone.

26. ... Rxc2! A devastating Exchange sacrifice.
27. Kxc2 Qxa2 28. Rd3 Rc8+ 29. Kd1 Qxb2 30. Rd2 Rc1+ 31. Ke2 Rxe1+ 0 : 1. For after 32. Kxe1 Bb4 there is nothing left for White.

And 侯逸凡 (Hóu Yìfán) finally said, says she, “Rook takes Knight”. Screenshot from the live stream.