1. d4 Nf6 2. c4 e6 3. Nc3 d5 4. Bg5 Be7 5. Nf3 O-O 6. e3 c6 7. Qc2 Nbd7 8. Bd3 Qc7

A mistake which loses a pawn.

9. Bxh7+ Nxh7 10. Bxe7 Re8 11. Bh4 dxc4 12. O-O Ndf8 13. Ne5 b5

The attempt to hold the gambit pawn as compensation cannot succeed.

14. a4 b4 15. Ne4 f5 16. Nc5 g5 17. Bg3 Qg7

Abandoning the c-pawns and White becomes two pawns ahead with a won game.

18. Nxc6 a5 19. Qxc4 Nd7 20. Nxd7 Bxd7 21. Ne5 Rec8 22. Qd3 Be8 23. b3

23. Nc4 first would have saved some trouble.

23... Rc3 24. Qd1 Nf6 25. Rc1 Bh5 26. Nf3 Rac8

This means an exchange of Rooks which is favourable to White. 26... f4 would be met by 27. Rxc3

27. Rxc3 Rxc3 28. Be5 Qh6 29. d5 Bxf3 30. gxf3 Rc8 31. dxe6 g4 32. fxg4 Nxg4 33. Qd7 Nxe5 34. Qxc8+

and wins.

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33. Rxd5

This was the critical position. Here White missed a win by 33. Bxg6 If Black recaptures the Bishop with 33... hxg6 (33... h6 34. Rxd5 Qxd5 35. Ne7+) (33... 33... Rxc6 34. Rxh7 Rxc2 35. Rh8#) 34. Qxg6 and mate by Rh8 cannot be prevented.

33... Qxc6 34. Qxc6 Rxc6 35. Rdh5 Ne5 36. Bxh7+ Kf7 37. Be4 Rc1+ 38. Kf2 Rd8 39. Ke2

McMahon decides to give up the exchange, rather than lose his b-pawn.

39... Rcd1 40. Rxe5 R8d2+ 41. Kf3 fxe5 42. b3 Rd8 43. Rh5 Kf6 44. Rf5+ Ke6 45. Rg5 Rf1+ 46. Ke2 Rf7 47. Rg6+ Ke7 48. Bd3 Kf8 49. Bc4 Rf6 50. Rg4 Re8 51. Kd3 a5 52. Ke4 Rf2 53. Rg6 Re7 54. Kd5 Rc2 55. h4 Rc3 56. Ke4 a4 57. Rxb6 Ra7 58. Kxe5 Rxe3+ 59. Kd4 a3 60. b4 Rg3 61. Re6 a2 62. Bxa2 Rxa2

It looks as if Steen has a decisive advantage, but McMahon battles on.

63. b5 Ra8 64. Kc5 Rxg2 65. b6 Rc2+ 66. Kb5 Rb2+ 67. Kc6 Rb8 68. Kc7 R8xb6 69. Rxb6 Rxb6!

Excellent technique.

70. Kxb6 Kf7

The pawn ending is a definite Black win, but White fought on and only resigned on the 80th move.

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