French Defense: La Bourdonnais Variation – Playing Against ...b6

The La Bourdonnais Variation is built around a simple idea: White uses 2.f4 to clamp down on the dark squares and prepare a quick d4, creating a broad pawn centre. After 3.d4, your pawns on e4, f4, and d4 give you a clear space advantage — but they also come with a responsibility: you must develop quickly so Black cannot undermine you with ...c5 or ...f6. Your most important piece in this line is the light-squared bishop, which belongs on d3, where it eyes the kingside and supports the centre. The engine's top continuation — Bb7 Bd3 c5 Nf3 — shows a typical fight: Black puts immediate pressure on d4 with ...c5, and your job is to respond with natural developing moves (Nf3) rather than panicking. You are slightly better, but only if you keep the tempo. Do not grab pawns prematurely; your edge comes from piece activity and central control.

The best move in the position is Bb7 — Black correctly develops the bishop to the long diagonal. Your job is then to meet it soundly. The engine's approved line runs: 1.e4 e6 2.f4 b6 3.d4 Bb7 4.Bd3 c5 5.Nf3. A few things to notice here: Bd3 is the natural square — it defends e4, supports the kingside, and doesn't interfere with your queenside castling. When Black plays c5, your best reply is Nf3, developing a knight and defending d4. Do not be tempted to advance d5 prematurely (closing the centre plays into Black's hands, as they wanted to force you to block the long diagonal). Keep the tension for now. If Black takes on d4 after Nf3, recapturing with the knight is perfectly fine. Your plan next will be 0-0, followed by ideas like c3 or possibly f5 if Black castles kingside. You're slightly better — trust development over aggression.

Black has several choices after 3.d4, and the statistics over 282,581 games show you score well against all of them. Here is the breakdown with your winning chances (White win % excluding draws): - Bb7 (247,893 games): White scores 50.8% — the main line, play Bd3 and Nf3 as shown above. - g6 (4,764 games): White scores 53.1% — a hypermodern try; meet it with Nf3 and Bc4, keeping central pressure. - Qh4+ (4,398 games): White scores 50.9% — a nuisance check easily parried by g3 or Nf3, after which you develop with tempo. - Ba6 (3,550 games): White scores 55.3% — this is the gift you are waiting for (see below). - c5 (3,131 games): White scores 52.4% — the most principled line; respond with Nf3 and a standard French setup. - Nf6 (2,667 games): White scores 54.3% — Black attacks e4; defend with Nc3 or Bd3. Notice that every single reply gives you at least a 50.8% score — you are never worse in practice.

The most important tactical insight from the statistics: Ba6 is a known mistake that loses roughly 1.1 pawns in evaluation — Black should have played Bb7 instead. When you see Ba6, Black is trying to trade off your light-squared bishop before it can settle on d3. Do not let them! The best response is to retreat to c4 (or simply develop with tempo). Black has wasted a move, and your bishop on c4 will be a monster, eyeing f7 and supporting a future e5 push. Your score jumps to 55.3% after Ba6 — your highest win rate against any of Black's replies. If you are studying this variation to gain a practical edge, this is the moment to know cold. When Black plays Ba6, think: