This was an invigorating round. Magnus Carlsen is the comeback kid--he lost to the world champion in a risky but assertive game in the previous round, but he was able to rout Vladimir Kramnik in this penultimate round. Kramnik greedily gobbled a poisoned pawn and lost the game as white because of his inferior pawn structure and poorly positioned pieces. As black, Veselin Topalov made an egregious error against Eljanov in the opening. Imagining that he would bust open Eljanov's kingside position, he placed a bishop and knight on the rim of the board, eventually sacrificing a minor piece with little or no compensation ahead in the horizon.
The answer in retrospect is simple: after Ra7 Qb5 and the exchange of queens, white has doubled b-pawns and black gets the b2 pawn. However, it is not always evident to find the best move under pressure.
