Calling

[JugglingReferee]

Agreed. You must see the play.

However, in football, we're told to make, for example, PI calls based on unnatural movement. You see it in the NFL all the time. WR goes up to catch a pass. DB has his right arm around the R's waist, the the R turns, mid-air, away from the ball (towards his right) as the ball approaches from the left. Flag comes out.

Could you do this in basketball? I think you could. I can't think of an example right now though.

I've used this one: two players in the air and they crash while airborne. One has the ball. The defender lands further ahead of where he jumped from. When you jump, it basically is in a parabola. While facing midcourt, you jump and your feet leave the floor at the foul line, and you land 1 foot closer to the 3-point line, you either did not jump straight up, or you were contacted from behind. If you were not contacted from behind, you must have not jumped straight up. If the shooter was disadvantaged, then logically you have a foul, even though you did not see the contact. I've explained this one to players and they've always fessed up.