Andy Enfield is the head coach at the University of Southern California, and he is one of the best basketball shooting coaches that you will find out there today. He has worked in the NBA as a skill development coach. The reason that this particular basketball drill is named after him, is because he gets credit for creating the drill.
This shooting drill is designed to allow the player to get up a lot of shots, and can be done on your own or with a teammate for competition. You want to practice coming into your shot the right way every time, and really focusing on your mechanics each time you shoot the basketball.