ECO A45. A chess opening with 10 known variations.
Every line in this family begins 1. d4 Nf6 2. Bg5 Ne4 3. Bh4, then branches. Each variation below has its own page with the full move order, the position it reaches, and a Stockfish evaluation.
All 2 lines can be practised free in the browser: pick a variation, walk it move by move in Learn mode, then drill it from memory until you can play it without prompting.
The Trompowsky Attack begins 1. d4 Nf6 2. Bg5 Ne4 3. Bh4. From there it branches into 2 named variations, each with its own move order and typical plans.
The Trompowsky Attack is catalogued under ECO code A45. Individual variations list their own specific code on their page.
Open any variation on Chess Ramp and use Learn mode to walk the line one move at a time, then Drill mode to replay it from memory. Practice runs in your browser with no account required.