Queen's Gambit Accepted - classical - Rubinstein variation
1. d4 d5 2. c4 dxc4 3. Nf3 Nf6 4. e3 e6 5. Bxc4 c5 6. O-O a6 7. a4
White pushes the queen's pawn to d4. Black pushes the queen's pawn to d5. White plays the c-pawn to c4.
Black captures on c4 with the queen's pawn. White develops the knight to f3. Black develops the knight to f6.
White moves the king's pawn to e3. Black pushes the king's pawn to e6. White develops the light-squared bishop to c4.
Black pushes the c-pawn to c5. White castles kingside. Black moves the a-pawn to a6.
White moves the a-pawn to a4.