Blocking

[carldog]

I've re-read definitions for Verticality, Guarding Position, and Foul...still have a question.

B1 has feet firmly planted, arms folded tight against torso, standing in a normal upright postion. Just before A1 steps by B1 to dribble past B1's position, B1 leans his large, upper torso to that side...and contact occurs. If no lean had happened, no contact would have happened. But A1's forward motion did initiate the contact with the leaning but stationary B1.

Experience tells me this is a foul on B1, always, always. Whether playing defense, screening on offense, it is a f-o-u-l on B1. Basketball is not played in the leaning position.

Is this correct?

What is the proper rule citation?

Thanks.