This Pitching Velocity Quick Tip covers effective foot contact on the rubber. This is a critical component to velocity because this is the foundation of force production. If you are going to support triple extension (3X) then you must make sure that during your stride, your weight is riding on your power pads. This is the area from the ball of the foot to just above the arc. If your weight is riding on this area then you will be able to finish 3x with an explosive ankle kick.
Those pitchers who do not have good foot contact on the rubber will shift their weight to their heel which will prevent 3x. Some pitchers will start with a good foot contact position but when they start their strides they shift their weight to their heel. To learn more about good foot contact please watch this pitching velocity quick tip.