Modern Defense: what to play after d4?

In the Modern Defense (ECO B06), the overwhelmingly primary continuation for Black is Bg7, completing the kingside fianchetto to put immediate pressure on the long diagonal. Selected in 94.3% of games across 61M recorded encounters, it also receives the engine's best assessment at +0.58. By developing the bishop to g7, Black contests the center indirectly while preparing rapid kingside castling.

Developing with Bg7

The move Bg7 represents the defining idea of the Modern Defense setup. Black cedes the center early to White's pawns, intending to undermine d4 and e4 from the flank. An illustrative continuation demonstrating this counterattacking theme runs Bg7 Nc3 d5 exd5 Nf6 Bc4, where Black strikes immediately at White's central footprint.

Transpositional and Alternative Move Orders

While Bg7 is the standard move, alternatives exist that adjust the timing of Black's setup. The flexible d6 represents the second most common choice, seen in 4.3% of games (2.81M recorded) with an evaluation of +0.69; a sample continuation runs d6 Nc3 Bg7 Be3 Nd7 Qd2, often transposing into Pirc Defense or standard Modern Defense structures. Players also occasionally delay bishop development using a6 (eval +0.81), continuing a6 c4 d6 Nc3 Bg7 Be3.

Immediate Central Challenges

Black can also opt to strike directly at White's central pawns on move two rather than delaying conflict. The move d5 occurs in 0.8% of recorded games (547K recorded, eval +0.81) and leads into d5 exd5 Bg7 Nf3 Qxd5 Be2. Similarly, c5 appears in 0.5% of games (336K recorded, eval +0.76), meeting central resistance in lines such as c5 d5 Bg7 c4 d6 Bd3. Nonetheless, Bg7 remains the dominant and statistically preferred path.