Standard Line

After 1. e4 g6 2. d4 Bg7, the developing move 3. Nc3 is the most direct way to keep White's classical pawn duo on d4 and e4 intact. The knight defends e4 in advance, so a later ...Nf6 or ...d5 gains no time, and it leaves White free to choose among f2-f4, Be3 with Qd2, or Bc4 depending on Black's setup. It does block the c-pawn, which rules out the c2-c3 plan against the g7-bishop that Geller's System uses. Wikibooks treats this position as the main line of the Modern. Black has conceded the center and must now find a constructive way to strike at it, or risk being overrun.

The usual answer, chosen in over two-fifths of games, is 3...d6, the Standard Defense, which keeps the hypermodern plan of pressuring d4 and e4 with pieces and pawn breaks. From there White picks between the Pseudo-Austrian Attack, 4. f4, typically met by 4...c6 5. Nf3 Bg4, and the more restrained 4. Nf3.

The alternatives differ considerably in character. 3...e6 is the second most common reply and can head toward Hippopotamus-type formations with the e- and d-pawns on the third rank. 3...c5, the Modern Pterodactyl, attacks d4 immediately at the cost of some risk; in practice it scores as well for Black as for White. 3...b6, the Mongredien Defense, prepares a double fianchetto. 3...c6 is a more passive choice that prepares ...d5 or queenside expansion, and it allows the aggressive 4. Bc4 d6 5. Qf3, aiming at f7. The rare 3...d5, known as the Lizard Defense or Mittenberger Gambit, strikes at the center at once; despite its scarcity in practice, engines list it among Black's best moves, alongside 3...d6 and 3...a6, the latter associated with ...b5 setups.

The position is among the more frequently reached named positions, with well over a hundred thousand Lichess games. White scores somewhat better than Black overall, and the engine assessment is a slight edge for White, consistent with the general view that Black's setup is flexible but cedes space. Play tends to be less forcing than in many open games, but White's options for a quick f2-f4 or a kingside attack mean that Black's choice of reply largely determines whether the game becomes a slow maneuvering struggle or a sharp fight for the center.