Stolen bases generally start when a pitcher is throwing a pitch. However, they can start when the pitcher attempts a pickoff, or when the catcher throws the ball back to the pitcher. David Peralta stole home when the Rockies’ catcher lobbed the ball back to the pitcher.
Safely advancing to the next base is not always scored as a stolen base. Exceptions are:
- Wild pitches and passed balls unless he was attempting steal as the ball left the pitchers hand.
- An error by the opposing team led to the advanced base.
- Defensive indifference (they don’t want to risk a wild throw to second or their lead is so large it does not matter).