It realy just comes down to practicing. My son did not do well on this event the first time he took the CFA. After much practice in our front yard, he did much better. I was the catcher/measurer and could not see what he was doing; it was a mystery to me when some of the tosses would duck flop. The one tip I found helpful was to make sure that he is applying the force through the center of the ball and not letting it spin off his finger tips to much. It's a balance between too much rotation, too much leaning back, timing, and balance. Get a tape measure, something for his knees, and do it every day for 10 min and he will get much better. I posted your question about three months ago. Good luck.