STEPPING TO A BASE
The pitcher, while touching the rubber, must step directly toward a base before throwing to that base. If a pitcher turns or spins off his free foot without actually stepping, it is a balk.
In stepping to a base, the pitcher must lift his entire non-pivot foot off the ground and bring it down in a location different from where it started and toward the base. The entire non-pivot foot must move in a direction and distance to the base. This will constitute a step. The pitcher is not allowed to lift his non-pivot foot up and bring it back down in the same spot where it started. In stepping, the heel of the pitcher’s free foot may not end up in the same spot it started.