How do you structure your divisions at AGSL?

We use grade levels to create our divisions at AGSL.  

A (Tee ball and coach pitch):   Pre- Kindergarten 4 to First Grade

AA (Machine pitch):  Second and Third Grade

AAA (kid pitch): Fourth and Fifth Grade

Majors (kid pitch): Six, Seventh, Eighth and Ninth Grade (if there is a Seniors Division - Ninth Grade will play Seniors)

Seniors:  Ninth to Twelfth Grade