Chess Openings Lab
a8b7c6d5e4f3g2h1

French Defense: Advance Variation, Main Line

The Advance French main line 5...Qb6 6.a3 sees White prepare b4, gaining queenside space and challenging the c5 pawn. Black chooses between 6...a5 to stop b4, 6...c4 to lock the queenside, and 6...f6 to hit e5.

Moves
1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6 5.Nf3 Qb6 6.a3
ECO
C02
Engine
+0.27 · level (Stockfish 17.1, depth 20)
Played
1,367 games in our lichess sample
White scores
50.3%

Key ideas for both sides

White

  • b4 is the point of 6.a3: it attacks c5, gains space and helps hold d4.
  • Against 6...c4, White plays Nbd2, Be2 and Rb1 to prepare b3 and open the queenside, then h4 for kingside space.
  • Against 6...a5, 7.Bd3 and castling come first; a4 later fixes the b5 hole for a white piece.

Black

  • 6...a5 rules out b4 for good, then ...Bd7, ...cxd4 and ...Nge7 line up on d4.
  • 6...c4 closes the queenside and sends the knight to a5, eyeing b3 and the dark squares.
  • 6...f6 attacks the head of the chain. After 7.Bd3 fxe5 8.dxe5 c4 9.Bc2 Bc5, Black's pieces are free.

Plans and pawn structure

With ...a5 the game stays a normal French fight around d4: Black piles up with ...Nge7-f5 and the c-file, and White uses Bd3, O-O and a4 to secure b5. With ...c4 the queenside is closed, so White switches to b3 or to kingside play with h4 and h5. With ...f6 the center opens and Black's bishop gets c5, but e6 can become weak.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position +0.27: level. Its three top choices for Black:

  1. +0.27 6...a5 7.Bd3 Bd7 8.O-O cxd4 9.a4
  2. +0.31 6...c4 7.Nbd2 Na5 8.Be2 Bd7 9.Rb1
  3. +0.32 6...f6 7.Bd3 fxe5 8.dxe5 c4 9.Bc2

Pawns, from White's side.

How it scores on lichess

1,367 rated lichess games reached this position; White scored 50.3%.

1200–159947.8%
1600–199949.1%
2000 and up52.9%

Light: White wins. Grey: draws. Dark: Black wins. About the sample.

Where it goes next

  • Advance Variation, Lputian Variation6...Nh6 · rare

How to play against it

Choose a structure and commit. 6...a5 is the most solid and keeps the d4 pressure. 6...c4 is sound but gives up the ...c5 tension, so be ready for b3 and kingside pushes. Avoid a passive ...cxd4 cxd4 that lets b4 come with ease.

Questions

What are the moves of the French Defense: Advance Variation, Main Line?

The French Defense: Advance Variation, Main Line starts 1.e4 e6 2.d4 d5 3.e5 c5 4.c3 Nc6 5.Nf3 Qb6 6.a3. Its ECO code is C02.

Is the French Defense: Advance Variation, Main Line good for White?

Stockfish 17.1 rates the position +0.27 at depth 20, which is level. In 1,367 lichess games from our sample, White scored 50.3%. A positional line for players on both sides who like long maneuvering games; it rewards knowing pawn structures more than memory.

What is the main idea of the French Defense: Advance Variation, Main Line?

White plays a3 to prepare b4, which would challenge c5 and free White's queenside. Black decides how to answer: stop b4 with ...a5, close the queenside with ...c4, or break with ...f6.

What should Black play next?

The engine's first choice is a5, with c4 and f6 close behind. 6...a5 stops b4 for good, keeping Black's pressure on d4 intact.

Updated October 2026. Sources and method.