{edit: I think this deserves to kick off Front Page Friday, even though it was from Thursday - The Beef}

A lot more goes into it than you might think. It takes tricked out cameras, modems over audio lines in those cameras, back-end computing power, and human intervention.

There's some skill involved in making sure the line does not draw on top of the players. If it is not a bright sunny day on a nice green field, it takes two guys and a lot of equipment to draw the line correctly.

This video explains all.