100% ????
Get real with that.
Upperclassmen playing behind 9th & 10th graders? I think you do not have a realistic view of your son's ability with respect to recruiting. If your 18 year old has a 14/15 year old playing ahead of him in Suffolk Division 1, not sure what college level lax your son has expectations of. This is not a knock of your son, but if your son played on the WM summer teams the past few years, he was given equal playing time & played with all the players from his position many college coaches watching....phones not ringing? He may just not be good enough. If he gave it his best, so be it, thats all you can ask...There are plenty of great schools that play lacrosse
and if you son plays WM varsity, there are spots for him, just do your homework & ask your HS coach is opinion.