Flip jump

Magnus Carlsen – Wesley So
6th Sinquefield Cup; Saint Louis, August 22, 2018
Semi-Tarrasch Defence D42

1. d4 Nf6 2. c4 e6 3. Nf3 d5 4. Nc3 c5 5. e3 Nc6 6. cxd5 Nxd5 7. Bd3 Be7 8. 0-0 0-0 9. Qe2 b6 10. Rd1 cxd4 11. Nxd5 Qxd5 12. exd4 Bb7 13. Be4 Qd6. The alternative is 13. ... Qh5 14. Be3 Na5 15. Bxb7 Nxb7 16. Rac1 Bd6 17. Qa6 Rfb8 18. h3 Qd5 19. Rd3 Qa5 20. Qc4 Qd5 21. Qa4 a6 22. Rdc3 b5 ½ : ½ Taimanov – O’Kelly, 5th Capablanca Memorial, Havana 1967. 14. g3!? It might seem to be quite an artificial novelty in a rather well known position. 14. ... Bf6 15. Bg5 Qe7. 15. ... Bxg5 16. Nxg5 h6 17. d5! exd5 18. Rxd5 Qc7 looks rather unclear, so So goes for a more defensive path. 16. Bxf6 Qxf6 17. Ne5! Rfc8 18. Qb5 Na5 19. Bxb7 Nxb7 20. Qd7 Nc5! 21. dxc5 Qxe5 22. c6 h5

23. Rd6! White decides to give up at least a Pawn to maximize the strength of his c-Pawn. Now So has to defend very carefully. 23. ... Qxb2 24. Rad1 Qc2! 24. ... Qxa2? wins a second Pawn, but loses a fatal tempo: 25. Qe7! and the terrific threat of c6-c7 is not avoidable without heavy concessions from Black. 25. h4 Rd8! Probably the simplest way to ensure a draw. Alternatively, it could be considered 25. ... b5!? 26. Qb7 Qc5! 27. Rd7 Rab8 28. Rc7! Rf8! 29. Qxa7 Qc2 with approximate balance (Stockfish’s analysis). 26. Qxd8+. If 26. Qb7 then (maybe) 26. ... Qxd1+ 27. Rxd1 Rxd1+ 28. Kg2 Rdd8 29. c7 Rdc8 (29. ... Re8 30. Qc6! Rac8 31. Qd7 may be far more dangerous for Black) 30. a4 which appears to be the maximum White can obtain, but still not enough to win, as after 30. ... Kf8 Black should succeed in freeing himself. 26. ... Rxd8 27. Rxd8+ Kh7 28. R8d7 a5. 28. ... Qxc6 29. Rxf7 a6 30. Rdd7 Qc3 should equally lead to a draw — and, eventually, to an easily drawn King and Pawn endgame. Whatever it is, So feels apparently more confident with the Queen on the board. 29. c7 b5 30. R1d2 Qc1+ 31. Rd1 Qc2 32. R1d4 f6 33. Rd2 Qc1+ 34. Rd1 Qc2 35. R1d6 Qb1+ 36. Rd1 Qc2 37. R1d6 Qb1+ 38. Kg2 Qe4+ 39. Kh2 Qc2 40. Rd2 Qc3 41. R2d6 Qc2 42. Rd2 Qc3 43. Re2 e5 44. Red2 b4 45. R2d6 Kg6 46. Kg2 Qc2 47. Re7 Qe4+ 48. Kg1 Qe1+ 49. Kg2 Qe4+ 50. Kg1 Qe1+ 51. Kg2 Qe4+ ½ : ½.