Take a look at this submission from Adrienne. A great example of [tag]matchup zone defense[/tag] that can work with all age groups.
After using this [tag]basketball[/tag] [tag]drill[/tag] I found my players were more likely to be more
aggressive in chasing loose balls and [tag]boxing out[/tag]!
Place basketball on floor in center of mid court or free throw line cicle.
Players should pair up with someone of equal size and speed.
Start with two pairs of players on each circle.
When the coach blows the whistle the player inside the circle attempts to [tag]box out[/tag] his/her partner and keep them outside the circle and away from the ball.
Switch allowing all players to be both inside and outside of the circle.