Rebounding - 3 on 3 continuous

Three lines of players. 1, 2 and 3 step out to be defensive rebounders against offensive rebounders 4, 5 and 6. Coach shoots, play 3 on 3 on a miss (or make) until a stop or score. On a stop, the defenders go off, the attackers are the next defenders; on a score, the defenders stay and the attackers go off. Next attackers are 7, 8 and 9.