ECO D40
5 named openings and variations are classified as D40. ECO (Encyclopaedia of Chess Openings) codes group openings from A00 to E99 by their opening moves.
- Queen's Gambit Declined: Semi-Tarrasch DefenseD401. d4 Nf6 2. c4 e6 3. Nf3 d5 4. Nc3 c5
- Queen's Gambit Declined: Semi-Tarrasch Defense, Levenfish VariationD401. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Nf3 c5 5. e3 Nc6 6. Bd3 Bd6 7. O-O O-O 8. Qe2 Qe7 9. dxc5 Bxc5 10. e4
- Queen's Gambit Declined: Semi-Tarrasch Defense, Pillsbury VariationD401. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Nf3 c5 5. Bg5
- Queen's Gambit Declined: Semi-Tarrasch Defense, Symmetrical VariationD401. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Nf3 c5 5. e3 Nc6 6. Bd3 Bd6 7. O-O O-O
- Queen's Gambit Declined: Semi-Tarrasch Defense, with e3D401. d4 d5 2. c4 c5 3. Nf3 Nf6 4. Nc3 e6 5. e3 Nc6 6. Bd3