Windup - disengage

[umpjim]

Searched for this topic and revived this thread for my question. When a pitcher in the windup steps back toward 2B with the non pivot foot and in so doing breaks contact with pivot foot to reposition I don't call anything unless the pivot foot comes high enough off the rubber that I judge an advantage in momentum is gained. I haven't had to fend off many complaints on this but when I do I'll tell the coach that the pitcher is or is not "running into the pitch". The call, BTW, is "do not do that."

When some pitchers start their windup facing 3B, the non pivot foot steps back to 1B and the pivot foot can also break contact, some coming a good bit off the rubber. There is no mometum gained toward the plate. Should I require these pitchers to maintain contact if there is no need for foot reposition? Is my "running into the pitch" rationale correct?