Eyal: <percyblakeney: The Corus site claims that van Wely had a theoretical win with 52. ... Kf8 instead of Kf7, but don't ask me how.>

Yeah - as it turns out, after swapping the a4 and b6 pawns, the following position reached in the game (with White to move):

click for larger view

is a draw, which Eljanov achieves by accurate play, whereas the same position with Black's king on f8 is won for Black. Go figure... apparently, 54.Rb7+ gains a crucial tempo for improving the position of White's rook in order to execute the strategy used by Eljanov of creating constant mate threats. With Black's king on f8 – and White's rook on the 6th rank - it wouldn't work, for example: 54.Kf6 Rf4+ 55.Kg5 Rb4 56.Ra6 a4 57.Kf6 Ke8 58.Ke6 Kd8 59.Kd6 Kc8 60.Kc5 Rg4 – and now 61.Kc6 fails to Rg6+.

Eyal: Another line which demonstrates nicely why the position reached after 53...Rxa4 should be won for Black with the king placed on f8 instead of f7 is:

54.Rb7 h4! (now that Rb7 isn't played with a check, Black gains a crucial tempo for advancing this pawn to the 4th rank, where it's defended by the rook) 55.Kf6 Rf4+ 56.Kg5 Rb4 57.Ra7 a4 58.Kf6 Ke8 59.Ke6 Kd8 60.Kd6 Kc8 61.Kc5 Rg4 62.Kc6 Kb8 63.Rb7+ Ka8:

click for larger view

In the game Van Wely played his rook to h4 rather than g4, so that Eljanov was able to draw later by Rb5; if he had played 60...Rg4, we could get a position similar to that of the diagram - only with the black pawn on h5, in which case White draws by Rh7. However, in the diagram position the fact that the pawn is on h4 and protected by the rook makes all the difference, since 64.Rh7 would lose to 64...a3 (e.g. 65.Kb6 Rb4+ 66.Kc5 a2).

http://www.k4it.de/index.php?topic=...

Eyal: <Xeeniner: why does Van Wely play 60...Rh4 --It seems to restrict the movement of his rook and pawn. What's the reasoning behind it?>

I think the basic reasoning is to defend the pawn. As I mentioned in an earlier post, if Black plays instead a move like 60...Rg4/f4, which doesn't restrict the movement of the pawn, then we can get further along the line the following position:

click for larger view

Where White draws with Rh7 - forcing Black either to give up the h-pawn (with White having time to stop the a-pawn as well), or allow his king to be subjected to constant mate threats (after, e.g., h4 Kb6). With the pawn on h4 instead of h5, this position would be winning for Black.