Queen's Gambit Declined: Baltic Defense, Queen Attack Deferred

The Queen's Gambit Declined: Baltic Defense, Queen Attack Deferred is a chess opening classified under ECO code D06 in the Closed & Semi-Closed Games family, arising from 1.d4 d5, including the Queen's Gambit, Slav Defense, and related systems. It is reached after 4 moves: 1. d4 d5 2. c4 Bf5 3. Nc3 e6 4. Qb3. The resulting position leaves black to move.