Shell Drill is a defensive drill focusing on backing up from their player and making sure that the offence doesnt get any easy buckets. The main points that you need to remember to play defence like this is, each defender should always have their eyes on the ball and their player, when the ball is driven baseline, every defender should move together in synchronicity, if the ball is passed, every defender should move whie the ball is in the air, and the key to all team defence is communication.
