Here I am in action as White in a recent game.
1.d4 Nf6, 2.c4 d5, 3.Nc3 dxc4, 4.e3
4...Nc6, 5.Bxc4 e6, 6.Nf3 Bd6
7.0-0 White plays safe 0-0, 8.e4 and now advances...
Black starts with 11...Bxd5, 12.Nxc6?? White goes very wrong. Black's bishop has just captured a knight 3 points, White then captures a knight of his own points balanced, but the Black bishop moves out of danger by capturing the knight 6 points V 3 points, or a piece down!!
See if you can spot the best sequence from the diagram after Bxd5.
12...Bxc6, 13.Re1 Be5 White resigns, there is little point playing on a piece down against decent players.
The best sequence is
12.Bxd5 Nxd4, 13.Qxd4 c6, 14.e5