A1 and B1 moving towards each other
 

B1 is guarding A1. B1 moves toward A1; A1 realizes and then moves toward and charges B1 in hopes of drawing a foul.

Which of the two players has requirements/limitations at the time of contact? Was that player meeting those requirements?

Smart play by A1

Well, I would say that B1 was required to not be moving toward A1 at the time of contact. But I was thinking that since B1 was the first who wanted to get to a desired spot and was then prevented by A1, that maybe A1 could be at fault for setting an illegal screen.

That makes it a double foul.

I have a foul on B1 without seeing it live. It seems like B1 was not in LGP and A1 is allowed some freedom of movement. The only problem I would have is if A1 threw his body into B1.

Peace

Illegal screen? This is going to be a block/charge situation. B1 did not have a legal guarding position by virtue of moving toward A1 at the time of contact. If B1 wants to get to that desired spot, then do so legally.

To be fair the NCAA did once use an interpretation about the ball handler setting a screen. Now that may not apply here but I do see the point he is trying to make. I do not feel that applies here but there is a play on the NCAA video this year that talks about setting a screen with a once ball handler. You even showed one of your NCAA videos there was a foul called on a ball handler that just passed the ball as well.

Peace

Oh, I'm perfectly aware that the ball handler can set a screen. You see this all the time when a cutter tries to rub his defender off a ballhandler, and the ballhandler tries to act like he's "just pivoting" into the defender when in actuality, he's setting a screen.

But in the situation above, it's going to be a block/charge situation IMO.

A1 could be setting a screen. You have to decide. Was B1 trying to cover another player who was cutting to the basket as in a pick-n-roll with A1 attempting to prevent B1 from staying with the player they were guarding? Short of an obvious screen attempt, B1 is guarding but not guarding legally.