[shawnz]

Don't forget about spin as well, which can significantly change the trajectory due to the Magnus effect

[mannykannot]

I would guess that if there is enough spin for the Magnus effect to be significant, it would also be significant with respect to the rebound, as the surfaces in contact are not frictionless. On the other hand, I am not sure there is much spin in most basketball shots, and, given a backboard designed without taking it into consideration, there would be no incentive to add spin.

[tomjakubowski]

Backspin is an essential part of a reliable jump shot, and topspin is employed on finger roll layups close to the rim.

[mturmon]

Better to account for gravity first, no?