 Anand castled queenside on move 14, which was followed by a knight exchange in the centre, after which Carlsen advanced his queen to d5 (see diagram).This enabled a trade of queens, and, to the surprise of commentators and the audience, Anand accepted it, rather than pressing forward with 18.Qg4.The resulting endgame was balanced; Anand exerted pressure on Carlsen's kingside pawn shield with his rooks, eliciting a repetition of moves and a draw.