[Raymond]

Originally Posted by BillyMac

Agree with "foot on the floor in the semi circle equals crossing the line", but what about something less than that? Foot crossing the plane of the free throw line (like many other free throw violations)? Arm crossing the plane of the free throw line (like a defender crossing the boundary defending a throwin)?

And if interpretation involves the plane of the free throw line, is it the plane on the front of the free throw line (closest to the basket), or is it the plane on the back of the free throw line (farthest from basket, the plane that the free throw shooter must avoid crossing with his foot)? Remember a plane has only two dimensions, and has not depth.

With apologies to Ricky Ricardo, "NFHS, I think you've got some 'splainin' to do."

I don't think anybody is asking for that particular explanation.