Modern Defense: Semi-Averbakh Variation, Pterodactyl Variation
Modern Defense: Semi-Averbakh Variation, Pterodactyl Variation is a chess opening with the ECO code A04, part of the Modern Defense family. It goes 1. Nf3 c5 2. c4 g6 3. d4 Bg7 4. e4 Qa5+. White opens with 1. Nf3 (the Zukertort/Réti knight move) and Black answers 1... c5. After 8 moves it is White to move. The lesson on the board explains every move of the line and lets you play it yourself; it is free.
The moves
1. Nf3 – White plays the knight to f3
1... c5 – Black plays the pawn to c5
2. c4 – White plays the pawn to c4
2... g6 – Black plays the pawn to g6
3. d4 – White plays the pawn to d4
3... Bg7 – Black plays the bishop to g7
4. e4 – White plays the pawn to e4
4... Qa5+ – Black plays the queen to a5, giving check
About the Modern Defense
Black plays ...g6 and ...Bg7 early, letting White take the centre and attacking it later. It is flexible and hypermodern.
The g7 bishop pressures d4 along the long diagonal.
Black strikes with ...d6 and ...c5 or ...e5 at the right time.
If Black waits too long, White's big centre and Be3, Qd2, h4 attack can crush.
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