Pitching Rules from the 2011 Little League Rule Book, Page 38 (Rules For Players Over the Age of 12 Have Been Removed)
(a) Any player on a regular season team may pitch (Note: there is no limit to the number of pitchers that may be used in a game.)
(b) A Pitcher once removed from the mound cannot return as a pitcher.
(c) The manager must remove the pitcher when said pitcher reaches the limit for his/her age group as noted below, but the pitcher may remain in the game at another position.
11-12 85 pitches per day
9-10 75 Pitches per day
7-8 50 Pitches per day
Exception: If a pitcher reaches the limit imposed in regulation (c) for his/her age while facing a batter the picher can continue to pitch until the batter is out, reaches base, or the final out of the half inning is made.
Note 1: A pitcher who delivers 41 or more pitches in a game cannot play catcher for the remainder of that day.
(d) Pitchers league age 14 and under must adhere to the following rest requirements:
If a player pitches 66 or more pitches in a day, four (4) Calender days of rest must be observed.
If a player pitches 51 - 65 pitches in a day, three (3) Calender days of rest must be observed.
If a player pitches 36 - 50 pitches in a day two (2) Calender days of rest must be observed.
If a player pitches 21 - 35 pitches in a day one (1) Calender days of rest must be observed.
If a player pitches 1 - 20 pitches in a day no (0) Calender days of rest must be observed.