Deadly intermediate moves

7/21/2010 – In the rook ending from the game Wang Yue-Nisipeanu, Black may be a pawn down, but his pieces are simply bursting with activity and are well coordinated. The passed pawn on the queenside is effectively supported by the king, and the rook is cutting the white monarch off on the first rank from the rest of the battle. With Black to move, can you work out an exemplary winning variation? Should the latter begin with 56...b4 or with 56...Kc3? Compare your analysis with the comments by Karsten Müller for ChessBase Magazine Online.