if (window.location.hostname == "chessmind.ai" && !window.location.pathname.startsWith('/embed/')) { document.write('<iframe src="https://www.googletagmanager.com/ns.html?id=GTM-TS8C2C58" height="0" width="0" style="display:none;visibility:hidden"></iframe>'); }

ECO D90

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

2 named opening lines are classified under ECO code D90.

Grünfeld Defense: Flohr Variation — 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3 Bg7 5.Qa4+
Grünfeld Defense: Three Knights Variation — 1.d4 Nf6 2.c4 g6 3.Nc3 d5 4.Nf3