[Ref in PA]

This is probably a play you would have to see to call correctly. If B1 steps in on A1 and A1 straightens up making body to body contact, I would either call the foul on B1 or have a no call. If A1 leads with his elbow, and the only contact is A1's elbow on B1's jaw (B1 being able to get out of the way with his body) then I would either have a no call, foul on B1 or a foul on A1. I can envision plays where even though there was contact, I would let the play go (with hopefully a lessoned learned by B1). I can also see in my mind plays where the contact by B1 warrants a foul call. I can also see plays where A1's elbow was on purpose and call a player control foul and possible a flagrant foul if the elbow was extremely severe. I would also have to answer in my mind if B1 was "acting" when the contact occurred.

Bottom line is yes, A1 owns his space above him, but when A1 stretches out, a little judgement comes into play. You would have to see the play to make the correct call.