Long sleeve undershirts
 

In HS basketball, players may wear a long sleeve shirt under their jersey, so long as it conforms with uniform rules. In NCAAW, you may have a long sleeve undershirt, but it must be compression. I think I understand one reason why now. Doing a HS game last night, where A1 is just inside the 3 point line on the wing, and his defender B1 is in good position, with a hand up to discourage the shot. A1 raises for a quick shot, and while bringing the ball and his arms up, B1 gets a single finger caught in one of the folds of the regular, non-compression long sleeve undershirt. It clearly affects the shot attempt and a foul is call. Maybe you had to be there to see it, but its one where I have no doubt that if the kid is not wearing that shirt (or the shirt is compression), the finger either barely grazes or entirely misses the arm, and a foul almost certainly isn't called.

I don't know if I even have a question here, just an observation of a play that I hadn't seen before. Has anyone else seen this or have an opinion on this play?

Did the defender move their hand/arm, or did they keep it vertical?

They moved in reaction to the shot attempt, I believe the defender's movement was technically illegal. That's actually another point of discussion that we had after the game, if the defender doesn't move, then it's all legal, but just looks like a nightmare. But anyways, I think the correct call by my partner was made, just a rare situation in which the offense was given somewhat of an assist by the undershirt.

Just to clarify, in NCAAW:

That's straight from our supplemental apparel guide on Arbiter.

As you were.