Point 1: The "human element" argument is highly dubious. Nobody ever sees a lousy call and says "Gee, that's terrific. Every blown call adds to the beauty and perfection of the game, because Human Element". Bad calls are undesirable, and robots would reduce them. If you really want unpredictability, you can program in an x% error rate, and then it'll at least be unbiased, so Greg Maddux doesn't get every bull**** call. Point 2: For whatever reason, umpires like to bait players into ejections. A robot will not take off his mask and follow an unhappy hitter back to the dugout, talking like a sailor all the way to show the crowd what a big man he is. Point 3: I don't get it, but some people seem concerned with how long it takes to play baseball games. (Total speculation, but:) I predict that robot umpires would cut game times by an appreciable amount, as follows: Scenario A: Close pitch is called a ball. Pitcher stomps around mound in protest to let umpire know he's full of it. Catcher walks out to mound to talk him down. Eventually umpire walks out to break up the conference, and catcher chews on him the entire slow walk back to the plate. Scenario A with robot umpire: Close pitch is called a ball. Catcher throws ball back to pitcher for next pitch, because there's nothing to argue with the umpire about. Scenario B : Close pitch is called a strike. Batter curses, steps out and mutters something about a blind pig. Umpire takes off mask and asks player what his problem is. Batter turns his back so as not to be ejected and walks in a circle. (optional: manager comes out, kicks some dirt around, throws hat, and gets crowd all fired up). Batter adjusts gloves, ankle guard, and crotch, spits in general direction of ump, and eventually steps back in for the next pitch. Scenario B with robot umpire: Close pitch is called a strike. Batter steps back into box for next pitch, because while an MLB hitter in the prime of his life could reasonably believe his vision is better than a fighter pilot (much less a 60-year old man standing 5 feet away and behind another man), the local community college can put together a sensor with better visual acuity than any MLB player that ever lived.