15U "AA" compete as a single season team that all 15U aged players have an opportunity to try out for. The "AA" season begins with tryouts in February / March and continues until potentially mid-August depending on the success of the team in Provincials and Western Canadians.
15U "AA" begins the season under "Fair Play" rules but transitions to "9-man ball" at some point in the season (usually around June 1st). Under 9-man, there is starting lineup and the non-starters may be required to be on the bench for the entire game
Rule 23.03 Any of the nine starting players may withdraw and re-enter once, provided such player occupies the same batting position whenever s/he is in the line-up. This player may reenter at any defensive position except s/he may not pitch twice in the same game. A substitute who is withdrawn may not re-enter.
Players on the try-out list for 15U AA do not need to attend Bantam A assessments.