Alekhine's defence - four pawns attack
1. e4 Nf6 2. e5 Nd5 3. d4 d6 4. c4 Nb6 5. f4
White plays the king's pawn to e4. Black develops the knight to f6. White moves the king's pawn to e5.
Black moves the knight to d5. White plays the queen's pawn to d4. Black plays the queen's pawn to d6.
White plays the c-pawn to c4. Black moves the knight to b6. White advances the f-pawn to f4.