ECO A00. A chess opening with 4 known variations.
Every line in this family begins 1. Na3 e5 2. d3 Bxa3 3. bxa3 d5 4. e3 c5, then branches. Each variation below has its own page with the full move order, the position it reaches, and a Stockfish evaluation.
All 1 line 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 Sodium Attack begins 1. Na3 e5 2. d3 Bxa3 3. bxa3 d5 4. e3 c5. From there it branches into 1 named variation, each with its own move order and typical plans.
The Sodium Attack is catalogued under ECO code A00. 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.