[Mark T. DeNucci, Sr.]

Originally posted by Dan_ref

So we can use this argument to say B1 has committed a foul as he runs by and trips over A1's outstretched leg, can't we? In fact, using your argument any player is perfectly entitled to stick his leg out and trip any other player whenever he likes, assuming time/distance constraints are met. If a player can outstrecth his legs to increase the size of this cylinder why can't he simply outstretch both arms to increase the size of his cylinder as well?

Anyway, even though it's not to be found in the rulebook I like your term - "cylinder of verticality". It reminds me of the "cone of silence".

The plays you describe in your first paragraph are already covered in the guarding and screening definitions and each case the foul would be on A1.

What is being debated is how the principal of verticality is to be applied. In the original play A1 has established a pivot foot and a legal position on the court. A player's cylinder of verticality starts at the floor and goes all the way to the ceiling. The diameter of a player's cylinder of verticality has to be include the players body. The rules also state that the defender cannot belly up on an offensive player and violate the offensive player's verticality.

Just because A1 has become slightly off-balance does not give B1 the right to infringe upon A1's cylinder of verticality. B1's stradling of A1's leg is a definite infringement of A1's cylinder of verticality.