Number of, and placement of rest days varies from tournament to tournament. For the Sinquefield Cup this year it is pretty straightforward. In a four player double round-robin the single rest day is halfway through the tournament.
In round 2 on Tuesday I played the Dutch against Aronian. He went for the unusual Bf4 variation, and when he allowed my knight to e4 I was already somewhat better. Black had all the fun in this game, but despite a promising position I couldn.t break through. I decided against the obvious exchange sacrifice Rxd3, as I had missed a critical resource for black later on. Aronian defended well, and it ended in a draw.
In the next round I played Nakamura, who was the sole leader after having beaten Kamsky in a tough and interesting fight. I think I had a small advantage early in the middle game, the pawn on c6 looked quite promising. It was probably a mistake to capture on b5. In the complications a few moves later I could not find any really good continuations and choose to sacrifice an exchange to reach a slightly dubious ending. Nakamura, who had played really well up to that point, might have posed even more difficulties for me just before the time control. After move 40 my passed b-pawn constituted enough counterplay.
He offered a draw a few moves later rather than advancing his e-pawn after which the position would become double-edged.
At the half way mark Nakamura has 2.5 points and I.m second at 2 points. Aronian and Kamsky have 1 and 0.5 points respectively.
Lots of sports on the rest day today. I.ve played tennis and soccer and watched baseball at the Busch stadium. Not much to celebrate for the St.Louis Cardinals, but the last inning home run was exciting to watch!
Important round tomorrow, I.ll play black against Kamsky and Nakamura has black against Aronian.
Magnus Carlsen, St. Louis, September 12th, 2013