[mikorym]

So I am guessing that the reason why this doesn't look like a sattelite dish is because 1) the focal point is not in the centre and 2) the ball doesn't rebound in straight lines.

Oh shoot, he does actually explain this exactly. He also mentions 3) speed of the ball. And then, 4) for lines that hit at the same point but with different trajectories and speeds, he takes the "average basketball shot".

The only other thing I am wondering about is what would happen if the ball were flat.