I'm 12. It's true that a 29.5 size basketball would make his game improve, but that would be a training ball for him because a training ball is a size bigger basketball then the one recommended for someone. 28.5 is the right size. I keep 2, a outdoor training ball (29.5) and a indoor regular ball (28.5).
they only use five
umm 13 year old girls should probabl use a 28 to 28.5...