French Defense: Exchange Variation, Monte Carlo Variation
The Monte Carlo Variation is the French Exchange with 4.c4, attacking d5 right after the pawn trade. White plays for an open game where Black may end up with an isolated d-pawn, while Black uses quick development and pressure on d4 to turn the tables.
- Moves
- 1.e4 e6 2.d4 d5 3.exd5 exd5 4.c4
- ECO
- C01
- Engine
- −0.16 · level (Stockfish 17.1, depth 20)
- Played
- 3,434 games in our lichess sample
- White scores
- 52.0%
Key ideas for both sides
White
- Develop with Nc3 and Nf3 so that cxd5 lands with pieces ready to recapture and support d4.
- Block a bishop check on b4 with Nc3, then unpin with Bd2 as in the engine lines.
- If Black takes on c4, retake with the bishop and accept an isolated d4 pawn backed by active pieces.
- Aim the queen and bishop at d5; an isolated black pawn there is a long-term target.
Black
- Develop fast with ...Nc6 and ...Nf6, both hitting d4 before White finishes castling.
- The bishop check on b4 pins the c3 knight and weakens its hold on d5 and e4.
- Taking on c4 with ...dxc4 gives White an isolated pawn on d4 that Black can blockade on d5.
- After cxd5 and a knight recapture on d5, Black's pieces sit well and White's d4 pawn is alone.
Plans and pawn structure
The c4 push guarantees an isolated pawn for one side. If Black recaptures on d5 with a knight after cxd5, White has an isolated pawn on d4, and Black blockades on d5 while trading pieces. If Black keeps the d5 pawn, White piles up on it. The engine lines favor Black's quick piece play: ...Nc6, ...Nf6 and the check on b4 hit d4 while White still needs to move the king.
What the engine plays from here
Stockfish 17.1 at depth 20 rates the position −0.16: level. Its three top choices for Black:
- −0.16 4...Nc6 5.Nf3 Bb4+ 6.Nc3 Nf6 7.cxd5
- −0.15 4...Nf6 5.Nc3 Nc6 6.Nf3 Bb4 7.cxd5
- −0.15 4...Bb4+ 5.Nc3 Nf6 6.Bd3 dxc4 7.Bxc4
Pawns, from White's side.
How it scores on lichess
3,434 rated lichess games reached this position; White scored 52.0%.
Light: White wins. Grey: draws. Dark: Black wins. About the sample.
How to play against it
As Black, do not take on c4 too early. Develop with ...Nc6 or ...Nf6, check on b4, and let White release the tension with cxd5 so the isolated pawn ends up on d4. Then blockade with a knight on d5 and trade pieces.
Questions
What are the moves of the French Defense: Exchange Variation, Monte Carlo Variation?
The French Defense: Exchange Variation, Monte Carlo Variation starts 1.e4 e6 2.d4 d5 3.exd5 exd5 4.c4. Its ECO code is C01.
Is the French Defense: Exchange Variation, Monte Carlo Variation good for White?
Stockfish 17.1 rates the position −0.16 at depth 20, which is level. In 3,434 lichess games from our sample, White scored 52.0%. A lively try for White players who like open positions and isolated pawn play, but Black's easy development makes it a fair fight.
What is the main idea of the French Defense: Exchange Variation, Monte Carlo Variation?
White hits d5 with 4.c4 to create an open, unbalanced game. Black answers with fast development and pressure on d4, often leaving White with the isolated pawn.
What should Black play next?
The engine's first choice is Nc6, with Nf6 and Bb4+ close behind. 4...Nc6 develops with an attack on d4 and keeps the bishop check on b4 in hand.
Related lines
Updated October 2026. Sources and method.