How to Play the French Advance: a6 as White

By playing 4.c3 you shore up your d4 pawn and prepare to develop your pieces without worrying about ...dxe4 or ...Bb4 pinning your knight. Your central pawn chain — d4 and e5 — gives you space on the kingside and clamps down on Black's development. The trade-off is that Black's a6 move prepares ...b5 or ...c5, striking at your centre from the queenside. Your job is to keep the centre closed long enough to launch a kingside attack. The engine's best plan — c5, followed by Nf3, Nc6, and Bd3 — builds a flexible setup: the knight goes to f3 to control e5 and g5, the other knight develops to c6 to pressure d4, and the bishop on d3 eyes the kingside. You're not rushing; you're outplaying Black positionally first.

The most played move in this position is c5 (36,988 games), which is also the engine's top choice. That means Black's strongest players know they need to challenge your centre immediately. After c5, your plan is to continue with Nf3, meeting ...Nc6 with Bd3. This setup keeps your pawn on d4 solid — you don't rush to capture on c5 — and aims to finish development before committing to action. White scores 47.1% from this line, which is below the overall average, so be precise: maintain the tension, castle quickly, and look for a later break with f4-f5 or a timely dxc5 followed by pressuring the isolated d-pawn.

Two of Black's most natural-looking moves are actually inaccuracies, according to the engine. Nc6 (played 7,410 times) loses roughly 0.8 pawns compared to the best move c5. b5 (5,297 games) loses about 0.6 pawns. Why? Nc6 develops a piece but blocks the c-pawn — the very pawn Black needs to challenge your centre. Without the c5 break, your d4-e5 chain remains unshakeable, and you gain time to build a kingside attack. b5 is more subtle: it tries to gain space on the queenside, but it neglects development and weakens Black's queenside pawns. Against both, your engine-line plan works beautifully: develop your knight to f3, your bishop to d3, castle, and prepare to roll your kingside pawns. Interestingly, White scores 52.4% against Nc6 and 52.3% against b5 — those extra percentage points are real.

Let's walk through the engine's recommended sequence: after 4.c3, Black plays c5, then White answers Nf3. Black will most likely play Nc6 now (developing naturally), and you reply Bd3. Stop and look at the position: your pieces are harmoniously placed, your centre is intact, and Black still has to solve the problem of their light-squared bishop (locked behind the pawn chain on e6). Your plan from here: castle, bring your queen to e2 or c2, and decide whether to capture on c5 (opening the position) or push f4-f5 to attack on the kingside. The engine evaluates this as +0.63 — a small but stable advantage. You're not winning by brute force; you're winning by having a clear plan while Black struggles to find active play.