There are three offensive players and three defensive players
Coach throws the ball to any of the three offensive players standing around the perimeter
Whoever is guarding the man with the ball closes out
The two other players get in proper man-to-man defensive positioning
Closeout with proper technique
Move on the air-time of the ball - be there on the catch
Maintain proper defensive positioning
You can add or subtract players to this drill (2 on 2, 3 on 3, 4 on 4, 5 on 5)
After the initial action, you can complete various defensive rotations against offensive actions such as:
Open and through vs down screens
Chase and space vs flare screens
DHO or PNR defense
Other scout actions