Queen's Gambit Declined: Been-Koomen Variation

Queen's Gambit Declined: Been-Koomen Variation is a gambit, classified under ECO code D50 within the Closed & Semi-Closed Games family. As with all gambits, one side sacrifices material early — usually a pawn — in exchange for development, open lines, or initiative.

The Closed & Semi-Closed Games group covers closed and semi-closed games — 1.d4 systems characterised by long strategic manoeuvring rather than early tactics.

Play reaches this position via 1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Bg5 c5, after 8 plies of opening development.

It is a variation of Queen's Gambit Declined: Modern Variation, which itself descends from the root opening Queen's Pawn Game.

It branches into 3 notable variations — Queen's Gambit Declined: Pseudo-Tarrasch Variation, Queen's Gambit Declined: Pseudo-Tarrasch Variation, Primitive Pillsbury Variation, Queen's Gambit Declined: Semi-Tarrasch Defense, Krause Variation.

In total, the branch covers 4 sub-variations across all depths.

Step through the moves on the interactive board below, review the live Lichess statistics, or play this position against Stockfish at one of six difficulty levels.