Mongredien Defense, with Nf3

After 1. e4 g6 2. d4 Bg7 3. Nf3, the move 3...b6 prepares ...Bb7 so that both bishops bear on White's center from the long diagonals. Black postpones ...d6, ...Nf6 and any central pawn move, which keeps the setup flexible. A later ...d6 and ...e6 would give a Hippopotamus-type formation. The drawback is that White, with the king's knight already developed, is left with a free hand in the center. The engine judges White to be clearly better. In practice the results are closer to even, though White still scores somewhat more.

The most common reply is 4. Nc3, which completes natural development and also heads the engine's list. 4. Bc4 develops the bishop toward f7. The engine also likes 4. h4, an attempt to exploit the fianchetto by pushing the h-pawn. 4. e5 gains space at once and takes the f6-square from Black's knight, but in online play it is the one main continuation where Black has scored better than White.