Sicilian Defense: Nimzowitsch Variation, Exchange Variation

The Sicilian Defense: Nimzowitsch Variation, Exchange Variation is a chess opening classified under ECO code B29 in the Semi-Open Games family, where Black responds to 1.e4 with something other than 1...e5, including the Sicilian Defense, Caro-Kann, and Pirc. It is reached after 4 moves: 1. e4 c5 2. Nf3 Nf6 3. e5 Nd5 4. Nc3 Nxc3. The resulting position leaves white to move.