This is a great drill to help your players learn how to play helpside defense and not get beat backdoor. As the defense, once the offense shoots backdoor I teach two things:
1. If the offense gets a step on the defense, quickly swivel your head (Putting it on your bottom shoulder) so you can see man and ball, and put out the bottom arm to prevent the backdoor pass.
2. If the defense is able to read the offense and can beat them to a spot, I teach getting in between the offense and rim with their arm bar up and prevent their cut to the room, forcing the offense to pop back out.
Another important factor once the coach starts the attack dribble is the aggressive stunt by the defense. I typically teach the defense to stunt two times to the ball. In a game situation, if it requires more than two stunts, adjust accordingly or look to see if the on ball defense is doing their job.