How to Create a Great Setup and Starter Step?
Source: https://protips.dickssportinggoods.com/sports-and-activities/baseball/baseball-pitching-tips-create-great-setup-starter-step
As a pitcher, you should be both balanced and comfortable when on the mound. You also want to be in control of your actions. You should have your eyes on the catcher at all times, which will help increase your control.
One thing you can do as a young pitcher to eliminate head movement and throw more strikes is to work out of the stretch. Working from the stretch will allow you to bring both feet together and have your hands set, creating a stable base from which to throw.
If throwing from the windup, there are two different techniques you can use on the mound. For the first technique, your feet and shoulders should be staggered at a slight angle. If you are a right-handed pitcher, you should stagger your left foot and shoulder slightly in front of your right foot and shoulder, while toeing the rubber. If you are a left-handed pitcher, it should be the opposite, with your right foot and shoulder slightly in front of your left foot and shoulder.
From this position, take a small starter step with your glove-side foot, pivoting the foot of your throwing arm into a position that’s parallel with the rubber, before finding your balance position. For a right-handed pitcher, you would take a small step to your left side with your left foot, then pivot your right foot to be parallel with the rubber. If you’re left-handed, you would take a small step to your right side with your right foot, then pivot your left foot to be parallel with the rubber.
In the second windup technique, you will have your body completely perpendicular to the plate. This means having both toes facing the catcher, with your shoulders square and eyes on the target. From this position, take a small starter step back with your glove side foot, again pivoting your throwing arm foot into a position that’s parallel with the rubber.
With these techniques, you will be utilizing a small starter step to begin the delivery while your movement stays compact and quiet. You want to eliminate large steps in the windup, which will create issues with balance and make it very challenging to consistently repeat the delivery.