The height of the net is determined strictly by the location of the serve. The net is lower in the center than at the sides. So a serve down the T has more net clearance (more margin for error) than a serve that goes out wide. An "At The Body" serve is defined as one that hits the center (1/2 way between each corner) of the service line.

We have attempted to estimate the height of the ball as it crosses the net using geometry, factoring in the effect of gravity, and even fudging some for air resistance. However, we did not attempt to estimate or include any effects from putting spin on the ball. Even if we could factor in those effects, no one can accurately describe how much spin they put on the ball and at what angle of rotation.

All estimates assume that the ball is on a path that would just hit the back of the service line (either at the T, at the body, or at the side corner).

These estimates are probably not absolutely accurate since there are many factors that we did not consider. However, they should be reasonably accurate for RELATIVE comparisons.