Help a beaten teammate, then recover to your own player.
Two defenders covering for each other — the moment individual defence becomes team defence. The rep forces the timing: help early enough to be set in the driver's path, then sprint back out when the ball is kicked.
In games: Stops the layup parade when one defender gets beaten, and cuts the blocking fouls that come from arriving late and moving — the helper who is set early takes the charge instead.
U12: half-speed dribbling from the coach, and late rotations are normal. U14–U16: expect help-recover-help on two swings and the talk-or-restart standard.
1 ball
Two offensive players (ball + one away), two defenders.
The heartbeat of team defence — two players covering for each other.
Coach dribbles at half speed to teach timing.
Let the offence swing the ball twice so the helper has to help, recover, then help again.
If you don't hear 'Help!' and 'Recover!' out loud, the rep doesn't count.