Chess Opening Theory/1. e4/1...g6/2. d4

Modern defence B06 Modern defence 2. d4 Since Black has not contested the centre yet, White takes more space. They are ready to develop their minor pieces. Control the centre with pieces Black would like to focus on development and attack the centre from a distance. ...Bg7 and ...d6 is the immediate plan, usually played in the order 2...Bg7 and 3...d6, though either way is possible. Black usually accepts a small centre of their own, with pawns on d6 and e6. The role of ...d6 is to control the e5 square and prevent White from pushing a pawn there. This means that the bishop (once fianchettoed) will be able to surveil the centre, and Black will eventually be able to play ...Nf6 without facing e5. 2...Nf6!? immediately is called the Norwegian defence. Without the protection a pawn on d6, the knight may be kicked with 3. e5!. This is usually played with the idea of a gambit 3...Nh5 4. Be2 d6 allowing 5. Bxh5 gxh5 6. Qxh5. Control the centre with pawns !? Having allowed White to establish their big two-pawn centre, it is difficult now for Black to contest it with ...e5 or ...d5. Black may prepare ...d5 with 2...c6. 3. Nc3 d5 is a transposition into the Gurgenidze system of the Caro-Kann defence. 3...d6 prevents White from pushing a pawn to e5 but it is insufficient to support Black playing ...e5 themself. 3. Nc3 e5? 4. dxe5 dxe5 5. Qxd8+ Kxd8 ++ and Black has a strictly worse Philidor. Black may instead consider a flank attack on the pawn centre. 2...f5?, the fianchetto gambit is bad. Black offers a pawn and weakens their kingside to deflect White's e-pawn, intending 3. exf5 d5 (not 3...gxf5?? 4. Qh5#). Attacking on the other flank is usually played in the order 2...Bg7 3. Nc3 c5!?, and is known as the pterodactyl defence. Theory table 2...Bg7 3. Nc3 d6 4. Be3 a6 5. Qd2 b5 6. f3 Nd7 7. h4 h5 8. Nh3 Bb7 9. Ng5 Ngf6 10. O-O-O e6 Standard line + 2. ... ... 3. f4 d6 4. Nf3 Nf6 5. Nc3 O-O Austrian attack(by transposition) 2. ... ... 3. c4 d6 4. Nc3 Nf6 King's Indian defence(by transposition) 2. ... ... 3. Nc3 c5 4. dxc5 Qa5 5. Bd2 Qxc5 6. Nd5 Na6 Pterodactyl defence + 2. ... c6 3. Nc3 d5 Gurgenidze system(by transposition) 2. ... f5? 3. exf5 d5 4. Bd3 Qd6 5. fxg6 hxg6 Fianchetto gambit ++ References See also Modern Defense