ECO D23
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 D23.
- Queen's Gambit Accepted: Mannheim Variation — 1.d4 d5 2.c4 dxc4 3.Nf3 Nf6 4.Qa4+
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 D23.