ECO D42
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 D42.
- Queen's Gambit Declined: Semi-Tarrasch Defense, Main Line — 1.d4 Nf6 2.c4 e6 3.Nf3 d5 4.Nc3 c5 5.cxd5 Nxd5 6.e3 Nc6 7.Bd3