Caissa Codex
D50

Queen's Gambit Declined: Been-Koomen Variation trainer

Back to the opening, all openings to practise or my repertoire

Type a move and press Enter: e4, Nf3, O-O, or from and to squares like g1f3 (e7e8q to promote). The board is also played with the mouse.

Practise the Queen's Gambit Declined: Been-Koomen Variation

Play Black's moves of the line from memory — 1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Bg5 c5 — and the trainer plays White's replies; "Play the other side" turns it around.

"Drill all" adds the 4 named lines that continue it, such as Queen's Gambit Declined: Pseudo-Tarrasch Variation, Queen's Gambit Declined: Pseudo-Tarrasch Variation, Primitive Pillsbury Variation, Queen's Gambit Declined: Pseudo-Tarrasch Variation, Canal Variation, Queen's Gambit Declined: Semi-Tarrasch Defense, Krause Variation.

Read about the line, its statistics on Lichess and Stockfish's evaluation on the Queen's Gambit Declined: Been-Koomen Variation page, or pick another opening in the opening trainer.

https://chesscodex.org/train/queens-gambit-declined-been-koomen-variation