Modern Defense: Mongredien Defense, with Nf3: Plans and Traps

Key ideas for both sides

White

4.Nc3 and h4, as in the top engine line, combine development with a flank push.
4.e5 gains space; Bf4 and Nc3 support it before Black attacks with ...c5.
Bc4 and a4 restrain Black's queenside after ...c6.
Use Bf4 to protect e5 and target c7 on the h2-b8 diagonal.

Black

...Bb7 pressures e4; White must decide between e5 and Nc3.
...c5 strikes d4, especially after e5 when the pawn chain loses support.
...Nh6 and ...Nf5 can hit d4 when White's pawn is on e5.
Meet h4 with ...h5 or ...h6 to keep the kingside closed.

Plans and pawn structure

With the knight on f3, White can push e5 quickly and use Bf4 to hold it. Black answers with ...c5 and ...Nh6-f5 to attack d4. If White prefers Nc3 and h4, the game becomes a race: White's h-pawn against Black's ...c5. The b7 bishop is strongest when e4 is still on the board.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position +1.14: a clear edge for White. Its three top choices for White:

+1.14 4.Nc3 Bb7 5.h4 h6 6.Bf4 d6
+1.08 4.h4 h5 5.Nc3 d6 6.Bc4 c6
+0.97 4.e5 c5 5.Bf4 Nh6 6.Nc3 O-O

Pawns, from White's side.

How it scores on lichess

1,857 rated lichess games reached this position; White scored 53.2%.

under 120059.7%

1200–159951.9%

1600–199953.1%

2000 and up52.7%

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

How to play against it

As White, choose between e5 with Bf4 and Nc3 with h4. Don't let Black play ...c5 and ...Bxe4 freely. As Black, have ...c5 ready the moment White commits to e5.

Questions

What are the moves of the Modern Defense: Mongredien Defense, with Nf3?

The Modern Defense: Mongredien Defense, with Nf3 starts 1.e4 g6 2.d4 Bg7 3.Nf3 b6. Its ECO code is B06.

Is the Modern Defense: Mongredien Defense, with Nf3 good for Black?

Stockfish 17.1 rates the position +1.14 at depth 20, which is a clear edge for White. In 1,857 lichess games from our sample, White scored 53.2%. A provocative choice for Black that demands accurate counterplay; White players who grab space get an easy edge.

What is the main idea of the Modern Defense: Mongredien Defense, with Nf3?

Black aims both bishops at the center, and White uses the f3 knight to support e5 or a quick h4. Black's counterplay comes from ...c5 against d4.

What should White play next?

The engine's first choice is Nc3, with h4 and e5 close behind. 4.Nc3 defends e4 and prepares h4, a natural way to use White's free hand.

Updated October 2026. Sources and method.

Modern Defense: Mongredien Defense, with Nf3