English Opening: King's English Variation, Closed System

The English Opening: King's English Variation, Closed System is a chess opening classified under ECO code A25 in the Flank Openings family, characterized by moves like 1.c4, 1.Nf3, or 1.f4, aiming to control the center indirectly. It is reached after 5 moves: 1. c4 e5 2. Nc3 Nc6 3. g3 g6 4. Bg2 Bg7 5. d3. The resulting position leaves black to move.