Four attackers have 10 seconds to shoot, they can't dribble or move until a shot is taken, then they can rebound. The three defenders must box out three attackers (it doesn't matter if the open attacker gets a rebound), and make 3 stops to get out.
Mike Fratello - attackers must make at least four passes before shooting, there should only be one open offensive rebounder, can optionally allow attackers to dribble after four passes (defend penetration).
Tubby Smith - defenders have to contest every shot and make two stops in a row to get out (a stop doesn't count if the shot was uncontested), don't have two on the ball (talk), attackers are stationary, take the first good shot, but 4 passes maximum.
Tom Izzo - 4 on 3 or 5 on 4 disadvantage, perimeter attackers can't move or dribble, weakside defender guards two.
Larry Shyatt - attackers play for the first open 3 or shot, one defender is guarding two attackers and yells "I got two", this is a man or zone defence drill.
Doug Porter - play to 6 points, the offence can shoot only from behind the three-point line (the shooter rotates to the top of the key as safety) and gets 1 point for every make, the defence gets 2 points for a stop and rebound.
See Scrimmage - 4 on 3, Rebounding - Illinois 4 on 3.