I played club volleyball in college, and officiated intramurals. Calling the live aspects of the game itself are pretty straightforward. Keeping track of substitutions, libero movement, rotations, and overlaps are the tough part and require a lot of thinking during dead ball situations. I tried taking the NFHS test a few months ago, thinking I could work this fall, but gave up after 15 questions. It was the hardest NFHS test I had taken, by far.