The antepenultimate round of the 2015 Sinquefield Cup was an eventful one, though the first two games to finish weren't particularly auspicious. Topalov - Giri and Caruana - Vachier-Lagrave were short draws, but the remaining three games were more interesting. Anand - So looked very promising for the young American. Unfortunately for him, but perhaps fortunately for chess aesthetics, he underestimated a brilliant idea of Anand's. After 27.Nc4!? So should have played 27...a4 instead of 27...Bxc5. The latter move was almost irresistible, and that was what Anand was counting on. After 28.Nxe6 Bb4 29.Nxg7!! White gave up material but created a kind of fortress, and the players called it a day just before the time control.
The two remaining games were decisive. Hikaru Nakamura was on a high note, having won brilliantly the day before and enjoying the white pieces against Levon Aronian. Strangely, though, he seemed completely unprepared for Aronian's opening, one which is a regular part of the Armenian's repertoire. Black wound up better, and although he squandered his edge Nakamura's errors in time trouble gave it all back with interest. White's 39th and 40th moves were serious errors, and Aronian had no trouble capitalizing in the second time control.
Aronian started the round tied for first with Magnus Carlsen, so if Carlsen could parlay the white pieces into a win over Alexander Grischuk they would remain tied with two rounds to go. This did not happen. Grischuk, like Aronian, won with Black (a common occurrence in the tournament) to catch up to Carlsen (and Giri and Vachier-Lagrave) at +1, a point behind Aronian. About the Carlsen-Grischuk game: the game was generally even until around move 32, when an inaccuracy followed by an error cost Carlsen a pawn in what was close to a dead-drawn ending. Grischuk's technique in the second time control was terrific at first, but as the players approached six hours of play and started to live off the increment things got sloppy. First Carlsen managed to fight his way back to a drawn ending, and then he almost immediately messed it up and lost. By the time they were finished they had been playing for six hours and 25 minutes, so it's not that surprising that they started to err. (My analyses of the round's games are here.)
Aronian is in great shape with two rounds to go, but with four players just a point behind it's by no means over. Here are the pairings for round 8:
The last two pairings are especially interesting. For a long time Aronian had great results against Anand, and with White and in much better form in the tournament he has grounds for optimism. On the other hand, Anand has had some good results against Aronian lately, and when they get into theoretical disputes it's often Anand who comes out on top. Aronian shouldn't get too confident, as even a wounded Anand can do some serious damage. Meanwhile, Carlsen is playing his favorite opponent. Can Nakamura hold, or better yet, win his first-ever game against Carlsen at a classical time control? Stay tuned...