The main purpose of a Drill, is to practice a component of the delivery that will help to correct a mechanical flaw. I also believe it is important to add resistance to a drill to help imprint the new muscle memory.
The drill below should be performed 2 – 3 days a week, for at least 3 – 4 months. The drill should also be performed after completing the “Flexibility Training” portion of the Fusion System which can be found in the Ace Pitcher Handbook included in the 3X Pitching Velocity Program.  You will also find a ton more drills in the 3X programs. Try to push each drill to muscle fatigue, if possible.What you will need to perform the drill is your glove, a hiking or weight belt and some resistance bands or tubing. All of these products can be purchased here at the Equipment Store.
The purpose of this drill is to learn how to develop more momentum in your lower half through triple extension (3X) and use that momentum to build torque in the core. Connect the bands to the belt and then to a fence or preferably have someone hold the bands.

Instructions:

Pic #1:

Start in the stretch position, with the bands held tight behind you.  Lift your leg and lead with your front hip towards the target as you drive the belt forward, as if you are pitching the ball. Remember to keep your head over your belt buckle as your hips move forward and do not let your back knee bend forward over your back toes. Now, move into the “Load” position (select “Load” to view). This will help you build more momentum.

Pic #2:

This picture does not show a good stride because of the frame restrictions. Triple extend your drive leg before your front leg lands into a full stride with at least a 6 inch drag line in your back foot. The goal is to generate as much power as possible, without letting your shoulders commit to the target. Drive your back hip through hard, by kicking your drive leg ankle through before your front foot lands. You should work hard to get your back hip close to your front knee and your back shoulder over your back leg when finished, like in the picture.

Pic #3:

If you are having a hard time holding your shoulders back, as you drive your hips forward, then use a broom stick to keep your shoulder back and loaded.
The goal of the drill is to train momentum by building as much power as possible through triple extension in your back leg. DO NOT let your shoulders travel with your hips. This will prevent you from using your hard earned power to build torque in your core, like in picture #2. You want to generate as much hip to shoulder separation as possible.
Most pitchers do not have any understanding of optimal core torque. If this is the case, when you hit Pic #2 it may feel awkward. Just make sure you are in the same position as the picture. This component is called “Triple extension and separation.” This drill should fatigue your hips and legs. Work Hard!

Purchase the 3X Pitching Velocity Program to add 5-10mph to your fastball with a ton more excellent drills like the Sled Drill.