The Main Line, 5.a3 Ba5 is a variation of the French, Winawer Variation, catalogued as ECO C17. The line runs 1. e4 e6 2. d4 d5 3. Nc3 Bb4 4. e5 c5 5. a3 Ba5, reaching the position shown below after 10 half-moves.
Both sides have pawns in the centre (White on d4 and e5, Black on d5), and one pawn capture is available, so the structure has not settled yet. Development is level at one minor pieces each. It is White to move after five moves.
On the French, Winawer Variation generally: One of the most complex French variations. Black pins the Nc3 with Bb4, leading to sharp pawn structures and dynamic play.
You can play through this variation move by move in your browser — Learn mode walks the line with an explanation at each step, and Drill mode replays it from memory so you find out whether you actually know it. No account is required.
See all 8 French, Winawer Variation variations →
The Main Line, 5.a3 Ba5 goes 1. e4 e6 2. d4 d5 3. Nc3 Bb4 4. e5 c5 5. a3 Ba5. It is a variation of the French, Winawer Variation and is catalogued as ECO C17.
The Main Line, 5.a3 Ba5 is ECO C17. ECO codes group openings by their move order, so nearby codes cover closely related lines of the French, Winawer Variation.
Stockfish evaluates the position after 1. e4 e6 2. d4 d5 3. Nc3 Bb4 4. e5 c5 5. a3 Ba5 at +0.61 at depth 18, which is a small but real edge for White. Engine evaluation is only a starting point — at club level the practical value of a line is mostly about whether you know its plans better than your opponent does.
Both sides have pawns in the centre (White on d4 and e5, Black on d5), and one pawn capture is available, so the structure has not settled yet. Development is level at one minor pieces each. It is White to move.