It needs to be done by age group and dob
example
girls or boys U-11 have to be born in 2004
it's simple
if your left back sorry but athletics should not be your top priority and if your parents puy you in school late your playing on grade

I just heard of a youth wrestler in 6th grade who is a youth state champ his parents are attempting yo have repeat grade so he can get his weight up and have more years on varsity