YouRang: As this game was being played, I was following it with the computer. I recall that the computer thought white had a draw on move 45, in this position:
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Here white played 45. Rf7+? Kg8 <forced> Ra7. That check on move 45 didn't accomplish much, and the rook actually was more tactically useful on the b-file, where it restricted the knight's movements. White should have used the opportunity to attack the knight with tempo: 45. Kd4! <forcing the knight to a square where it has less defensive presence> The knight has 3 choices:
(1) 45...Na4, 46. Ra7 Nb2 <only move!> 47. Nb5 <the a-pawn falls and black is better> (2) 45...Nd1, 46. Rb8+! <with perpetual check! If the king hides at g6, the rook moves to the e-file and takes Pe6, and the perpetual check continues. If 46...Ke7 47. Rb7+ Kd8, then 48. Nf7+! Kc8 49. Nd6+ Kd8, and its another perpetual!> (3) 45...Ne2 46. Ke3! Rc2 <making room for ...a2, and still guarding knight> (diagram:white to move)
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47. Rf7+! Kg8
48. Re7! a2
49. Re8+ <and now the same perpetual check described above cannot be avoided> Playing 45. Rf7+? doesn't lead to the perpetual because the black knight can get to d5 where it stops the check at e7. | 
Kibitzing
sac: 51...h4
