Semi-Slav Defense: Main Line

The Semi-Slav Defense: Main Line is a chess opening classified under ECO code D46 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 10 moves: 1. d4 d5 2. c4 c6 3. Nc3 Nf6 4. e3 e6 5. Nf3 Nbd7 6. Qc2 b6 7. b3 Bb7 8. Bd3 Be7 9. O-O O-O 10. Bb2. The resulting position leaves black to move.