About this opening
Queen's Gambit Declined: Orthodox Defense, Bd3 Line is an opening in the Encyclopedia of Chess Openings,
classified under code D66. ECO group D (D00–D99)
covers closed games and semi-closed games beginning 1.d4 d5, covering the Queen's Gambit, Slav, Grünfeld and related queen-pawn structures. This particular variation is reached
after 15 half-moves from the
starting position, with the move sequence 1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Bg5 Be7 5. e3 O-O 6. Nf3 Nbd7 7. Rc1 c6 8. Bd3.
It belongs to the Queen's Gambit Declined family.
Within that family this is a level-2 branch (the Orthodox Defense → Bd3 Line line). The immediate parent line is Queen's Gambit Declined: Orthodox Defense, transitioned via 8.Bd3.
The opening sequence in prose form: 1.d4 d5, 2.c4 e6, 3.Nc3 Nf6, 4.Bg5 Be7, 5.e3 O-O, 6.Nf3 Nbd7. From this position the encyclopaedia records no further canonical continuations — practical play branches into unnamed transpositions or returns to the parent line for alternative ideas.
Use the interactive board above to walk through the moves position-by-position. Click any move in the navigation to step backwards, or use the keyboard arrow keys. For statistical data — how often master-level players have reached this position, White's win-rate, draw frequency, Black's score — see the panel in the right column.
Caissly's coverage of D66 extends through every named sub-variation in this line and across all four locales (English, Spanish, Portuguese, Russian). Where editorial commentary exists for a specific variation it appears as the page body; otherwise the page presents the structural data, board, and statistics as shown here.