ECO D54

ECO D00–D99 — Closed and Semi-Closed Games: 1.d4 d5 queen's pawn openings and the Grünfeld Defense.

1 named opening lines are classified under ECO code D54.

• Queen's Gambit Declined: Neo-Orthodox Variation — 1.d4 Nf6 2.c4 e6 3.Nc3 d5 4.Bg5 Be7 5.e3 O-O 6.Rc1