They're all huddled around home plate. If the player doesn't touch home plate, he'll be declared out and obviously if that's the difference in the game, it's of utmost importance that he touches the plate. So the umpire is staring at the plate to make sure the player touches.
They're not lined up on the edge of the grass, they're lined up in such a way that Home Plate is clearly visible - and that's what the umpire is staring so intently at. Here's a better view: http://www.washingtonpost.com/blogs/nationals-journal/files/2012/10/werth7.jpg They're allowed to be out there as long as (1) they don't interfere with a defender (irrelevant here, since the ball is out of play and the batter-runner may advance to home without the liability to be put out), and (2) they don't assist the batter-runner (think third-base coach pushing a runner back to the base). What's the umpire watching for? To make sure the batter-runner touches home plate. Once he does, assuming he touched the other bases legally - other umpires looking at them - the game is over. If he fails to do so, he can go back and make sure of it, but if he fails to do so and proceeds to the dugout, he can be called out for abandonment of his last legally-touched base (third). If that were to happen, then you'd continue as though he'd been put out in any other way - in this case, there would have been one out in the home half of the ninth. EDIT: This took me more than four minutes to write, apparently. I had to go find a picture Sorry, Dayton Ref!
Thanks. I could have figured it out from that photo. It was the perspective of the other one that buffaloed me.
Think offside is hard for the moms to understand? Can you imagine calling one of these in a U9 game at a tournament. The parents must go ballestic.
They don't use the infield fly rule for kids that young. Double plays are rare and there is no such thing as catching a fly ball with ordinary effort.
After the infield-fly call that so upset fans in Atlanta (which, by the way, I think was called correctly, contrary to popular wisdom), MLB's official Twitter handle changed its description to remove the line: "We don't understand the infield fly rule, either."