French Defense: Tarrasch Variation, Open System, Süchting Line
The Süchting Line is 4.c3 in the Tarrasch Open System, where White props up d4 with the c-pawn. After the trades on d4 and e4, White often ends up with an isolated d-pawn, which Black aims to blockade while White seeks active piece play.
- Moves
- 1.e4 e6 2.d4 d5 3.Nd2 c5 4.c3
- ECO
- C07
- Engine
- −0.21 · level (Stockfish 17.1, depth 20)
- Played
- 574 games in our lichess sample
- White scores
- 53.5%
Key ideas for both sides
White
- Recapture with 5.cxd4 and keep the d4 pawn as a source of space and outposts on e5.
- Use a3 to stop ...Bb4+ and keep your pieces coordinated.
- Develop with Nf3, Bd3 and short castling to support a kingside attack.
- Avoid trading too many pieces, since an isolated pawn gets weaker in the endgame.
Black
- Trade on d4 and e4, then develop with ...Nf6 and ...Bb4+ as the engine lines show.
- Put a knight on d5 to blockade White's isolated pawn.
- Trade pieces to weaken White's isolated pawn and aim for a better endgame.
- Watch for White's attacks on the kingside before trading.
Plans and pawn structure
After the trades on d4 and e4, White has an isolated d-pawn on d4. White's plan is quick development, active pieces and an attack on the kingside, using e5 as an outpost. Black wants to blockade d5 with a knight, trade pieces and target the isolated pawn in the endgame. If Black gets too passive, White's attack can be strong. If White trades too much, the d4 pawn becomes a weakness.
Where the engine's main line heads: White has an isolated queen pawn. White has an isolated d-pawn: no white pawns on the c- or e-file to support it.
What the engine plays from here
Stockfish 17.1 at depth 20 rates the position −0.21: level. Its three top choices for Black:
- −0.21 4...cxd4 5.cxd4 dxe4 6.Nxe4 Nf6 7.Nxf6+
- −0.20 4...dxe4 5.Nxe4 cxd4 6.cxd4 Nf6 7.Nxf6+
- −0.10 4...Nc6 5.Ngf3 cxd4 6.cxd4 dxe4 7.Nxe4
Pawns, from White's side.
How it scores on lichess
574 rated lichess games reached this position; White scored 53.5%.
Light: White wins. Grey: draws. Dark: Black wins. About the sample.
How to play against it
As Black, trade on d4 and e4 and develop with ...Nf6, ...Nc6 and ...Bb4+. Blockade d5 and trade pieces. Avoid leaving your kingside without defenders while White's pieces gather.
Questions
What are the moves of the French Defense: Tarrasch Variation, Open System, Süchting Line?
The French Defense: Tarrasch Variation, Open System, Süchting Line starts 1.e4 e6 2.d4 d5 3.Nd2 c5 4.c3. Its ECO code is C07.
Is the French Defense: Tarrasch Variation, Open System, Süchting Line good for White?
Stockfish 17.1 rates the position −0.21 at depth 20, which is level. In 574 lichess games from our sample, White scored 53.5%. A line that suits White players who like isolated pawn positions, while Black needs patient blockade technique.
What is the main idea of the French Defense: Tarrasch Variation, Open System, Süchting Line?
White supports d4 with c3, but after trades White often has an isolated d-pawn. Black blockades it and aims to trade pieces.
What should Black play next?
The engine's first choice is cxd4, with dxe4 and Nc6 close behind. 4...cxd4 trades in the center and prepares to leave White with an isolated d-pawn.
Related lines
Updated October 2026. Sources and method.