Scandinavian Defense: Anderssen Counterattack, Collijn Variation

The Scandinavian Defense: Anderssen Counterattack, Collijn Variation is a chess opening classified under ECO code B01 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 5 moves: 1. e4 d5 2. exd5 Qxd5 3. Nc3 Qa5 4. d4 e5 5. Nf3 Bg4. The resulting position leaves white to move.