Grand Tour

This week I conclude my coverage of the St Louis leg of the million dollar Grand Tour.
 
Carlsen-So: Sinquefield Cup, St Louis 2015 (see diagram 1)
 
Although Carlsen is a pawn down here his knight is so much better than Black’s bishop that this small material imbalance is essentially irrelevant. 29 a4 Bd8 30 Rd4 Kf8 31 Rfd1 Rc6 32 Ne3 Bb6 33 Nc4 Bxd4 34 Nxa5 This zwischenzug regains the pawn. 34 … Qb6 35 Nxc6 Bc5 36 Qd5 e3 37 a5 Qb5 38 Nd8 Ra7 39 Ne6+ Ke8 40 Nd4 Carlsen could have terminated the game more swiftly with 40 Nxc5 Qxc5 41 Qg8+ Kd7 42 Qxh7+ Kc6 43 Qxg6 when the pressure against d6 kills any black counterplay. 40 … Qxa5 41 Qg8+ Kd7 42 Qxh7+ Kc8 43 Qg8+ Kb7 44 c3 bxc3 45 Qb3+ Qb6 46 Qxb6+ Kxb6 47 bxc3 Bxd4 48 Rxd4 Kc6 49 Kc2 Ra2+ 50 Kd1 Rf2 51 Ke1 Kd7 52 Ra4 Ke6 53 Ra8 Rh2 54 c4 Kf7 55 Rb8 Ke6 56 Rg8 Black resigns
 
Nakamura-Grischuk: Sinquefield Cup, St Louis 2015 (see diagram 2)
 
Nakamura won an instructive endgame in the last round, gradually driving his opponent into zugzwang.