Verticality is an area where referees judgment has improved considerably over the past few seasons. However there are two areas where hard work is still required. Verticality with the Hands and Arms. A defensive player must keep his hands and arms vertical within his cylinder whilst defending an opponent. Players are moving their hands and arms forward out of the cylinder as the offensive player commences his upward motion and contacting the shooter's arms. Once contact occurs the arms are raised vertically. A foul should be called. Apply the cylinder principle throughout the game in all situations. Bellying-Up. Be alert to the defensive player showing verticality with his arms in the air whilst moving slightly forwards, into the offensive player, with his lower body. Determine if the defender established an initial legal guarding position with both feet on the floor, facing his opponent and on the spot first. A defensive player is allowed to jump VERTICALLY from a legally established position on the floor and whilst in the air is entitled to occupy the space within the vertical plane from the floor to the ceiling within his cylinder. A defensive player should not be penalized for leaving the floor in order to play legal defense. Contact which occurs between two players jumping vertically, side by side, is more likely to be incidental and deemed a 'no-call'. Tall players should not be penalized because of their athletic abilities to block shots and take rebounds in the air. The offensive player should not be allowed to use his 'free' arm to clear out the defender's arm(s) nor break the plane of the defensive player and initiate contact with the defensive player within his cylinder. In the low post position be alert to the defender's arm bar being used to push the offensive player away from the basket as he turns to shoot (hook shot or fade away jump shot).