FED Rules
From windup position pitcher stands with pivot foot (right foot) in contact with the LEFT SIDE (when facing the plate) of the rubber, and the toes in front of the imaginary line. Begins windup and slides his foot to the front edge as he is turning. I have never seen it before. Everything I've read indicates it's legal. Curious as to whether or not there are old CBs that cover this type of action and if in fact it is legal.