The corridor of certainty

In cricket there is a term ' the corridor of uncertainty. It is the line just outside off stump when a well directed ball will have a batsmen in two minds about whether the let the ball go, or try and play a defensive shot. The perfect delivery is one that will either hit the stumps if the ball is left, or takes an edge if the player tries to defend.
The only reason I mention this is to show the following game. I originally saw it in "Improve your Chess in 7 days" by IM Gary Lane, and the finish was particularly striking. In fact the whole game is well played by White (22.Nb1!), but when the Black king to f6, 31,g4 leaves it trapped in the 'corridor of certain mate'.


Xie Jun (2515) - Larsen,Bent (2560) [B08]
Veterans-Women Monte Carlo (1), 1994

1. e4 g6 2. d4 Bg7 3. Nc3 c6 4. Nf3 d6 5. h3 Nf6 6. a4 O-O 7. Be3 Nbd7 8. Be2 e5 9. dxe5 dxe5 10. O-O Qe7 11. Qd3 a5 12. Qc4 Re8 13. Rfd1 h6 14. Nd2 Nh7 15. Qb3 Ng5 16. Nc4 Nc5 17. Qa3 Nce6 18. Qxe7 Rxe7 19. Nb6 Rb8 20. Bg4 Re8 21. Bxg5 hxg5 22. Nb1 Bf8 23. Nd2 Bc5 24. Ndc4 Bxb6 25. Nxb6 Kf8 26. Rd2 Ke7 27. Rad1 Rf8 28. Nxc8+ Rfxc8 29. Rd7+ Kf6 30. Bxe6 fxe6 31. g4 1-0