Billy Tubbs fullcourt man
Build the entire defence from fullcourt man pressure (100M). Trapping is normally optional, but can be required ("A"). If you don't trap the inbounds pass they will clear out, and 100M doesn't work.
How quickly you can find your man is key. Every player that crosses or interchanges is a switch, defenders get inside position.
X4 is all over the inbound passer, shading to the middle to make him throw to the short corner. X1 is in a denial position on 1, seeing ball and man, inside hand on him, send him to the short corner, don't let him catch the ball. X2 has the same position on 2, sending him to the short corner. If 1 and 2 stack, X1 and X2 touch them. X1 and X2 sometimes face guard, trying to take a charge.
If 3 goes up, X3 denies. Offside deep defender X5 is the safety. The further your man is from the ball, the further you are from your man. If 5 goes up, X5 can't deny and be safety, he will pick up 5 on a catch.
Off-ball defenders deny one pass away regardless of where the ball is on the floor.
On the inbounds pass, X4 jumps to the ball, staying in the passing lane to 4 (don't jump too far back), in a pistols position. He has to pick up 1 if X1 gets beat.
The on-ball defender is close enough to touch the dribbler, puts great pressure on the ball, the back of his wrist or hand on the dribbler's waist, and always head on the ball, turn him, turn him, turn him - don't let him go where he wants to go. Release and run if you get beat.
X4 has the option to go trap the inbounds pass (not to the long corner). Trap coverage is sideline, middle, and deep. It's a zone once the ball is trapped.
X2 has 2 and 4, when in doubt cover the guy who can hurt you the most. If 1 turns his back, X2 can move up towards 4 looking to pick off a pass. You want steals, not dead-ball turnovers.
How much ground can X5 cover? If 5 goes deep, X5 has to be able to get a pass to him.
A defender trailing the play can go trap near halfcourt, either side of centre.
On the fast break, the fifth player up the floor can take his time, he's the safety.
See Billy Tubbs fullcourt zone (100Z).