I was curious as to how much speed you could gain from leading with you hip with optimum effectiveness. Assume the pitcher just leads with his shoulder.
And what I said in my reply to your previous post holds true here. When you drive off the lower half of your body and your legs, hips and torso all get into the act, your arm and shoulder will just go along, and you’ll be throwing with less effort and a lot more power. You will probably pick up speed as you get into this.
Leading with the shoulder makes it more difficult to get good hip and shoulder separation and that’s where a lot of your power comes from. Of course, leading with the front hip isn’t enough - you’ve got to do all the other things well, too.