@floating123 you might consider a new thread, since this is kind of a new topic. To answer your questions – my son did not know he wanted to play soccer in college (he had a dim grasp of what college was!) in 8th grade. However, he did have a burning desire to be the best soccer player he could possibly be, whatever that meant.
I suspect different schools have different policies with regards to athletic recruitment, and also it depends on the sport. Some schools have chosen to focus on certain sports and not others. So, it depends! But it is not anything like college recruiting. At the schools I know best (Millbrook and Hotchkiss), they are interested in fielding competitive teams, but they are primarily focused on the academic side of the application.
As for when recruiting starts – for college? Again, it depends on the sport, the sex of the player, and the level of the player. Top D1 men’s soccer recruits are on schools’ radar in 9th grade and 10th for sure. Lower level D1 a bit later, D3 mostly junior year into senior year.
Let me quickly say these are broad generalities and there are always exceptions to the more typical recruiting path.
As for boarding school recruitment, kids that get “recruited” are kids that would make varsity in 9th grade, even being a starter in 9th grade. In soccer, they would have been playing club soccer for a few years already. You would reach out to the coach, and express interest, and hopefully have something – video, on the roster of a well known team – that is proof of the level of play. And then I expect the coach’s support is helpful, but is not enough to get you in. This is speculation on my part, but for example, if the school decides it needs another 9th grade boy day student, and there are four good candidates to choose from, the school would choose the boy who also can play on the soccer team – he brings one more thing the school that maybe the others don’t bring.
Anyway, I truthfully don’t know a ton about prep school athletic recruiting; we only applied to a couple of schools for non-soccer reasons. If you were really pursuing athletic recruiting, you’d figure out which schools excel/emphasize your sport, and apply to them, but we didn’t do that.