Alekhine Defense: Steiner Variation

The Alekhine Defense: Steiner Variation is a chess opening classified under ECO code B02 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 Nf6 2. e5 Nd5 3. c4 Nb6 4. b3. The resulting position leaves black to move.