BARDEN’S CHESS PROBLEMS

Magnus Carlsen v Erwin L’Ami, Tata Steel Wijk aan Zee 2011.

One big characteristic of world champion Carlsen is that he squeezes the last drop out of every position and keeps on setting traps against a tiring opponent. In today’s puzzle, the Norwegian continued to play the endgame of rook and knight against rook, which theory reckons is an easy draw for the lone rook player. Here, Carlsen has set a last trap. Black’s g4 king is in check and there are just three candidate moves, Kh5, Kh3 and Kf3. Two of these keep Black’s draw safe, the other loses by force. Poor L’Ami selected the loser. Can you spot the dud move and how Carlsen punished it? (Answer on page 60.)