Us lacrosse uses 9.1 as their cut off date. Most age based tourneys go by us lacrosse rules. However, most tourneys are moving towards grade based not age based. Us lacrosse can't do anything about this. It is up to the tourney director to determine their own rules. Us lax has nothing to do with private tourneys. Finally, having grade based tourneys makes it easier for colleges to recruit because they dont have to guess what grade the kid is in.