Having your child repeat 8th grade in order to improve their standing on the lacrosse field is pathetic. Common practice within the MIAA and Baltimore club scene. Birthdates for the majority of the players in the MIAA have been made public at one time or another. Yes - there are 17 year old Freshman in the MIAA. Maryland state records don't lie. Keep living the fantasy.
I don't know of any that turned 17 during the school year but there are many 16 year old freshman. A few good players did pre-first but many of them re-classed in Middle school. Gilman, StPauls and particularly BL do this regularly with students who are transferring in. A few pretty good players at a Howard county club 2020 team transferred into BL and all of the sudden they are 2021 and playing for crabs. St Pauls kid 2019 other club now 2020 at BL and FCA. Happens all over.
