This is a drill I used often at Princeton to make the team work together as a defensive unit. It also helps the offensive player rely on his own skills in case he gets in a situation during a game in which he needs to dig himself out of a hole.
The drill is quite simple. Five defensive players switch off as one offensive player brings the basketball up court. The defense swarms, trying to get only a steal. The offensive player does not shoot, only dribbling and using his speed and dribbling skills to avoid turning the ball over. Do not call fouls or backcourt.
Defensive Teamwork and Offensive Individuality
At least 6

The basketball drills are licensed under a Creative Commons License.
TLC: Pål Degerstrøm 2000-2008