Watch the background of this clip and you will see a coach get beaned in the head with a ball during some ground ball drills.
I don't post this because I get any particular glee from seeing someone get blasted in the head with a ball. I post it because it reminds me of when I witnessed the same thing in High School, playing for the mighty Tigers of Lemoore High.
I was on the JV team and we were doing infield/outfield drills. If you're not familiar, it's a routine practice drill, that looks pretty complicated, with balls flying around everywhere, but once a team has it down, it runs like a smooth machine.
Well, one day the machine broke down, and our coach got a baseball upside his head. The offending first baseman could do nothing but stare at the ground while he paced in circles. Now, Coach was a good guy, but he had an extreme temper. In fact, when we were on the freshman team, we witnessed one of his outbursts on the team bus, and it made us practically scared to play for him. But like I sad, he was a good guy, as long as you weren't beaning him in the head or showing up to practice in a golf visor and stirrups with ankle socks (that's another story). Needless to say, once he had his bearings, we got an earful and practice was cancelled.
So the lesson here is simple: if you want out of practice, bean your coach in the head.