One of our managers has been training Rebounding for his guards (20y old and 183 cm; 19y old and 185 cm). One of them popped in second of four weeks of training (probably had high sublevel). The other didn't pop in those four weeks.
On the other hand, I'v seen 220 cm and 19y olds pop in RB 5-7 times in 9 weeks of training RB. Height makes such a difference it's not even funny.