Check swings

Question
I would like to know how a 2nd base umpire located behind the pitcher can call a check swing a strike? I understand how a 1st and 3rd base umpire can do it but If the home plate umpire has to go to the second base umpire in a 2 man system, how can his angle be better than the home plate umpire?

Answer
Truth is, he can't! Its definitely the drawback to three (or two) man crew. The umpire has to stand there though to have any chance of seeing a play at second. Hopefully the call will go your way. Often times you can't count on the 2nd base umpire to 'punch out' the hitter on a check swing. If he does, he's showing up the guy behind the plate.
I understand your frustration. The best umpires are never seen.
Jon