Legal move?
 

Player A3 is standing in the free throw half-circle waiting to receive a pass from the wing. Player B3 comes up and legally establishes a guarding position facing A3 and right in front of him. B3 has hands up, feet well planted and spread, but not too widely. A3 is shorter (by quite a bit) and quickly steps to A3's left and then back in behind B3, receives the pass, and dribbles down the key for a quick shot. B3 was startled, and didn't react. I think he thought that A3 was completely clueless, and didn't anticipate any real action. Now the question: If B3 was fast enough, could he have tried to step in front of A3 and take a charge? A3 stepped forward and to the left, but since they were both completely stationery prior to A3's move, does B3 need to leave any time or distance? what legal defense did B3 have?

4-24-5 paraphrased says:

Time and distance are relevant for guarding someone without the ball. The guard must move obliquely, and not forward into the offensive player.

I see no reason this can't be a charge as long as the above requirements are met.

Okay, here's what I'm getting at. A3 is a lot smaller than B3. I think A3 has an advantage since it's going to be a lot easier for him to get around B3, than for B3 to block him. Does that seem reasonable?

Theoretically, B3 could take a charge here.

Realistically, just thinking about how this sort of play would unfold, I can't really see this as being possible. Unless B3 has psychic abilities and can anticipate what A3 is going to do, than he probably wouldn't be able to get into position to take the charge.

Does that make sense?

yea, it makes sense, and it's what I was asking. A3 is my son. I'm trying to coach him how use his (small) size to his advantage. His coach has him standing at the top of the key, not doing much. He's getting good at driving and shooting, but needs to be able to avoid defenders, most of whom are quite a bit bigger than him. I'm trying to show him how to sort of fake them into thinking they've got him stopped and then tricking them into either fouling him, or letting him pass.