Age classification for all ages...MUST present player pass with photo before EVERY game, for all ages below college. As players progress through HS, USA Lacrosse can use JV A, JV B, Varsity AA, Varsity A, Varsity B. U8 through U15 can use same AA,A,B competition level designations. I would not use the Soccer example of September 1 as a cut off, Keep it like hockey with 1/1/xxxx - 12/31/xxxx cut-off dates. Both more physical sports than soccer (although yes, soccer people - soccer is a physical sport as well) | 
