[KenWittlief]

brings up an interesting question though: if they did decide to 'instrument' the field so refs can review a call, then what would it take?

High speed video cameras that can capture a thousand frames per second (slow motion video)?

sensors in the ground that can detect the ball hitting the plate, or the dirt?

stereoscopic (3D) video that would give the reviewer good depth perception?

Lasers everywhere, like alarm systems in museums, that will detect when a ball has crossed a line?

Im sure the ball flight path could be tracked with millimeter accuracy. How would you like that contract at your company?