It's About Time . . .

[Emperor Ump]

I think there are 3 things which prolong games:

1. A good portion of that is game management by the umpire. Keeping the ball in play, always having baseballs ready, not calling time unnecessarily, ending visits in a timely manner, managing the between inning situations...
   
2. Next thought would be pitching. If the pitcher can put it in there the game will go quicker. A good pitcher will stay in longer and need less visits.
   
3. Finally defense if the defense can make the expected routine plays things will move along well. If they can make the tough plays things will go even quicker.

Unfortunately as umpires we have no control of 2 & 3, but you can shave half an hour or more off of a game by managing the game well as an umpire.