Modern Defense: Pterodactyl Variation

The Modern Defense: Pterodactyl Variation is a chess opening classified under ECO code B27 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 g6 3. d4 Bg7 4. Nc3 Qa5. The resulting position leaves white to move.