Correct me if I am wrong, but the table below is from the US Lacrosse website.Isn't the difference between U11 and U9 potentially a 24 month difference? How does age based change anything?
2015 Age Grouping Quick Reference Table
Birthdate Age Bracket Born on or after 9/1/1999 U15 Born on or after 9/1/2001 U13 Born on or after 9/1/2003 U11 Born on or after 9/1/2005 U9
This would make things worse. You could potentially have a team 2 grades higher playing you. US Laxcrosse would have to come up with something better then this before anyone would want to switch from grade based.