I agree with Jim that there will never be a perfect age cut-off for everyone, since there will always be someone who is just barely on the wrong side of that cut-off. I am curious about one thing, however. I have never seen an AAU competition where they used one year age divisions - all of the ones I've seen used two years. Personally, I think that a maximum 24-month range in birthdates is pretty reasonable; however, I would be curious to know how well it works at AAU events that use one year divisions.