Pick N roll or Moving Screen

[TigerBball]

So, lets define the sitch a little better. A1 sets legal screen facing B2, A2 uses screen well, B2 runs right into screen. B1 switches to A2, thus creating the opportunity to roll. But as I coach, I do not like my guy to roll and release the defender, because then the defender can catch up to the play. I want them to roll and pin (hold) the defender with their backside, like a block out. Thus creating space between the basket and A1 with B2 behind.

Now, as the pass is made, A1 will move toward the pass and hopefully have a nice lane to the hoop.

So is the pivoting and pinning, with contact all the way, but without displacement, just holding the defender in one spot legal.