Stress
Sports fans can be difficult. They love their (insert name of sport here). They love their team.
This, then, is where things get stressful. You have to know what your job is as the operator of your specific camera so that, when the director calls on you, you've got the exact shot—be it a home run or a coach who's flipped his lid—needed for the broadcast.
Say you get confused and think you're working Camera 4 instead of Camera 6, and you miss an epic moment in the game. Not only will you be in big, bad trouble with the director, but a million sports fans parked in front of their television sets will rise up as one angry mob because you destroyed their viewing experience.