When pitching with runners on base, you've got to deliver the baseball to the plate in 1.3 seconds or less from the set position.

Why 1.3?

Let's do some simple math: Quick base runners can usually swipe a bag in under four seconds. A catcher can usually receive the ball and make a throw to second base (also known as a catcher's "POP time") in roughly two seconds.

1.3 + 2.0 = 3.3

4 - 3.3 = 0.7

This gives either your catcher or your teammate covering second base a 0.7 second margin of error. And to throw good runners out, every tenth of a second counts.