Caissa Codex
D05

Queen's Pawn Game: Colle System 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 Pawn Game: Colle System

Play White's moves of the line from memory — 1. d4 d5 2. Nf3 Nf6 3. e3 e6 4. Bd3 — and the trainer plays Black's replies; "Play the other side" turns it around.

"Drill all" adds the 3 named lines that continue it, such as Rubinstein Opening: Semi-Slav Defense.

Read about the line, its statistics on Lichess and Stockfish's evaluation on the Queen's Pawn Game: Colle System page, or pick another opening in the opening trainer.

https://chesscodex.org/train/queens-pawn-game-colle-system-3