he ball goes out-of-bounds (OOB). Everyone has a line he covers, so no problem, right?

Minus #4: Line coverage

In Part IV, we saw the example of Lead being too wide (at the arc) to know for sure the proper call for OOB on the other side of the lane. Line coverage problems also happen on the sideline for Trail.

Trail's coverage is not the corner, but rather the paint. If the ball is lost OOB on Trail's line, who makes the call? Lead is on-ball, so you would think Lead would make it.

Of course, just get it right we say. Yet, the coverage of lines using the pro mechanic can get confusing compared to normal coverage in 2-person or NFHS 3-person mechanics.

Put yourself in the position of the Lead.  You have a closely guarded count on A2 in the corner, not five feet away. Trail is looking off-ball into the paint. All of a sudden there is a loose ball, but it is on Lead's blind side where Trail — if he was looking in that direction — could see.

Arms move. Body is against body. There may have been contact. The ball goes OOB on the sideline, but no one has a good look at what happened. Who is the ball off of, and whose possession is it?

Continued...