Modern Defense: Mongredien Defense, with Nc3: Plans and Traps

Key ideas for both sides

White

4.Be3 and Qd2, as in the top engine line, prepare long castling and Bh6 to trade the g7 bishop.
h4 and h5 open the h-file against Black's king.
Use Nf3 and Bd3 to support e4 against the b7 bishop.
Against ...c5, d5 gains space and locks the long diagonal of the g7 bishop.

Black

...Bb7 pressures e4 and adds a second bishop on a long diagonal.
...d6 and ...e6 or ...c5 create a solid but cramped center.
Meet h4 with ...h5 to stop h5, as in the engine lines.
...a6 and ...b5 can create counterplay against White's long castling.

Plans and pawn structure

White has a free hand: Be3, Qd2, O-O-O and h4-h5 is a natural attacking plan. Black's bishops on b7 and g7 aim at the center, but they need pawn support from ...d6, ...e6 or ...c5. If White locks the center with d5, the b7 bishop's diagonal is blocked. White scored 58.1% in the sample.

What the engine plays from here

Stockfish 17.1 at depth 20 rates the position +1.12: a clear edge for White. Its three top choices for White:

+1.12 4.Be3 Bb7 5.Qd2 d6 6.O-O-O a6
+1.01 4.Nf3 d6 5.Be3 Bb7 6.Qd2 e6
+0.96 4.h4 c5 5.d5 h5 6.d6 Bxc3+

Pawns, from White's side.

How it scores on lichess

459 rated lichess games reached this position; White scored 58.1%.

under 120059.1%

1200–159955.3%

1600–199957.7%

2000 and up67.4%

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

How to play against it

As White, develop quickly with Be3 and Qd2 and then start the h-pawn. Keep e4 well defended so the b7 bishop has nothing to bite. As Black, don't let White get both h5 and Bh6 for free.

Questions

What are the moves of the Modern Defense: Mongredien Defense, with Nc3?

The Modern Defense: Mongredien Defense, with Nc3 starts 1.e4 g6 2.d4 Bg7 3.Nc3 b6. Its ECO code is B06.

Is the Modern Defense: Mongredien Defense, with Nc3 good for Black?

Stockfish 17.1 rates the position +1.12 at depth 20, which is a clear edge for White. In 459 lichess games from our sample, White scored 58.1%. An unusual setup for Black that gives White easy attacking chances; it suits players who like hypermodern play and know the ideas.

What is the main idea of the Modern Defense: Mongredien Defense, with Nc3?

Black places both bishops on long diagonals with ...b6 and ...Bb7. White uses free development and an h-pawn attack to exploit Black's slow setup.

What should White play next?

The engine's first choice is Be3, with Nf3 and h4 close behind. 4.Be3 prepares Qd2 and long castling, aiming for Bh6 and an h-pawn attack.

Updated October 2026. Sources and method.

Modern Defense: Mongredien Defense, with Nc3