Sicilian Defense: Closed

The Sicilian Defense: Closed is a chess opening classified under ECO code B25 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 6 moves: 1. e4 c5 2. Nc3 Nc6 3. g3 g6 4. Bg2 Bg7 5. d3 d6 6. f4. The resulting position leaves black to move.