Queen's Gambit Declined semi-Slav - 5.Bg5 dc
1. d4 d5 2. c4 e6 3. Nc3 Nf6 4. Nf3 c6 5. Bg5 dxc4
White advances the queen's pawn to d4. Black advances the queen's pawn to d5. White pushes the c-pawn to c4.
Black advances the king's pawn to e6. White develops the knight to c3. Black develops the knight to f6.
White jumps the knight to f3. Black moves the c-pawn to c6. White develops the dark-squared bishop to g5.
Black captures on c4 with the queen's pawn.