The next question is what about your sliders? Rick Pauley teaches his students to slide their drag foot across. Another way of doing it. I don't agree that rocking while throwing a pitch causes gym foot. Or is illegal, when you rock your feet stay on the rubber, clearly this is the case.
Agreed. Rocking causing a gym step is like blaming spoons for making people fat. Improper mechanics is the cause of a gym step. Despite the claims of a previous post rocking in and of itself is certainly legal.