Catcher pick-offs/end-of-play

[DanSmith]

To answer the second question, defining "the play" is a scorekeeping function - which is not covered by the rules and is not a responsibility of the umpire(s). Once a catcher has received a pitch, play is still live. A runner may attempt to steal a base, the defensive team may attempt to pick off a runner, etc.

For example, the fourth ball of an at bat is called. The batter is therefore awarded first base on the walk. "Play" is still live while the runner heads to first, and after the runner gets to first. For example, the batter-runner may immediately round first and attempt to take second if he wishes.

"Play" ends when an umpire calls time, declares a dead ball, or calls the third out of an inning. "Play" does not resume until the home plate umpire declares so.