Red #1 establishes legal guarding position by having two feet on the floor facing the offensive player.  Once he has established legal guarding, he is permitted to jump straight up. 

In this drive from the wing the center official does not stay connected with the play.  Once the initial defender is beat the center official needs to move to find the secondary defender.  In the lead position, this is a good patient whistle calling across the paint when there was not a whistle from the center official. Be aware of calling across the lane on plays that are at the rim on the opposite side of the paint in the three man system.

The lead official shows great whistle discipline by not blowing across the lane.  Watch as Gold #5 establishes and maintains legal guarding position throughout the play.

White #35 establishes legal guarding position by having two feet on the floor facing the offensive player.  Once he has established legal guarding, he is permitted to jump straight up.  Both the lead and center officials understand the fundamentals of verticality having a NCC (no call correct) on the play.