Beginning the Windup
Many young pitchers have difficulty with balance. One of the reasons is poor mechanics at the beginning of their windup. Many are taught to take their rocker step (the initial step behind the rubber) straight back. The reasoning for this is that you want the pitcher to take his weight straight back so that all of his weight is coming forward toward the plate when the pitch is delivered.
One problem with this advice is that the pitcher’s weight shift is stopped during the knee lift (thus his weight does not continue forward after stepping back). The pitcher’s weight should be back when the front knee is lifted and he should be able to balance on one leg. A second problem with this advice is that many young pitchers lose their balance going from a straight back rocker step to their pivot (with their other foot) inside the rubber.
Young pitchers should begin their windup by positioning themselves (if right-handed) so that their body is facing between third base and home plate (or between first base and home plate if left-handed). The rocker step should only be a few inches and angled toward first base (for righties). Importantly, the pitcher should try to keep his head and weight over his front foot. This will allow him to make a smooth and balanced pivot into the knee lift part of the windup.