There's too much over-coaching when it comes to pitch design. Over-coaching leads to changing arm action & release - which can increase the risk of injury & decrease pitch performance. Pronation occurs naturally - don't force it. Pedro explains this perfectly. With a change-up, your middle finger becomes your index finger, your ring finger becomes your dominant finger. If this shift doesn't create the change in speed, arm side movement, or depth your looking for, don't force pronation. Simply sh