Proper mirroring on a three-pointer...

[Freddy]

Originally Posted by Rich

Here's the problem with 2 arms in the air marking a 3:

Are both officials taking that jump-shooter back to the floor?

An arm up tells me that official is responsible for the shooter up and down and I can focus on rebounding action. If they're both going up, who's watching rebounding? The L?

If both go up, the C should drop it and readjust his focus. Pregame this.

If this post had "Like" button I would click on it.

Another problem with it:
While four eyes were on the competive matchup over there, who was surveilling off-ball activity?
Other problems exist "with it", but I'll let others contribute now that I've over-spoken on the issue.