Baseball, by the Rules

Kyle Leahy, and a few other St. Louis Cardinal infielders, make their way off the field after getting the third out of the inning.
The Inning Ends
Once the defensive team has accumulated three outs, the half-inning comes to a close, and the two teams switch sides. The umpire starts a timer1 ; said timer will usually start as soon as the final out is recorded, but there are exceptions to this. For example, if the inning ends with the catcher on base, at bat, or on deck, then the umpire will usually wait until the catcher gets back into the dugout to start the timer2.