George Mason University
a) Thumbs down - trap the receiver of the first pass in the frontcourt (trap down).
b) Thumbs up - trap the dribbler on the first dribble over the centreline.
There are two trappers, two interceptors and a goaltender.
X1 follows the pass to 2 and traps down with X2. Weakside X3 rotates up top to take away ball reversal, is the reversal interceptor (RI). Weakside X5 moves up to the high-post area (the next most likely pass), becomes the high-post interceptor (HPI, often a big). X4 is the goaltender (GT), he fronts 4. Any post-to-post screen is an automatic switch.
Get "3 to the ball" on every trap, the two trappers must have their three teammates get ballside and in the action, working together. Positions are the same after trapping on the wing regardless of the attacking set.
On a reversal pass it's one trap and out. If you leave your man to go trap, you must run out of the trap to find the open man, and run to where your help comes from.
X1 rotates out to find the open man. If X5 decides to take 3 because he is closer, then X1 would go where his help came from and take 5.
However, if the other team continues to attack with a pass to the corner, trap again. X2 leaves to trap (his man made the pass). X1 is RI, X3 is still HPI, and X5 is GT.
Trap the first dribble over halfcourt. The defence inches towards the dribbler as the ball approaches midcourt.
X4 is interceptor #1, up the sideline or possibly to the high post, X3 is interceptor #2, also anticipating a pass to the high post plus reversal. X5 is the goaltender.
(Note that interceptor roles are different for thumbs up, there is usually a pass up the sideline to defend.)
A pass to the wing out of the trap immediately becomes Thumbs down.
X1 follows the pass to trap with X4. X2 is RI, X3 is HPI, and X5 is still GT.
X1 would rotate out of the trap.
On a pass to 2 in the corner, X1 chases the pass to trap with X2.
X4 is RI, X2 is HPI, and X5 is GT, he would front if 5 is ballside. Again, 3 to the ball.
On a secondary break, teams are usually looking to reverse the ball, not make a wing-entry pass. Trailer trap is normally called after a time-out. X4 becomes the first trapper.
X4 follows the second pass to trap. X1 is RI, X2 is HPI, X5 is GT, fronting 5.
On a pass out of the trap, X4 would rotate to find the open man.
X4 leaves to go trap as soon as the ball crosses halfcourt. He is not able to trap one dribble over halfcourt, but can still trap at the wing.
X3 and X3 are the interceptors (X2 opens up), X5 is the GT. Put 1 in a position where the only likely pass is back to 4, X3 anticipates that.