In the game as white against co-leader Ian Nepomniachtchi I went for 1.e4 and 3.Bb5 against the Sicilian.
As planned I got a small but pleasant advantage out of the opening, and my opponent spent quite some time early on (at least compared to his normal rapid mode of play).
He quickly managed to improve his position by playing d5, but it was still somewhat tricky for black. My problem was that I struggled finding a proper plan. He had two pawn weaknesses against my single weakness on the queenside. This left him tied up at the queen side, but my own king was far to vulnerable to facilitate an efficient kingside attack.
He defended very well and when I finally could win a pawn he had sufficient counterplay. I had the choice between taking on a5 or c6. The latter would at best give me a rook ending a pawn up (that he most probably would be able to draw), and I went for Rxa5 instead having missed his immediate combinational counterplay yielding a perpetual check. Draw.
Aronian played a fine game against Svidler to take the sole lead before the last round. I.m shared 2nd and has black against Nakamura tomorrow at 1pm local time.
Magnus Carlsen, Moscow, November 24th, 2011