English Opening: King's English Variation, Keres Defense

The English Opening: King's English Variation, Keres Defense is a chess opening classified under ECO code A21 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 3 moves: 1. c4 e5 2. Nc3 d6 3. g3 c6. The resulting position leaves white to move.