Hoping not to offend anyone, I will add my two cents. My daughter is only a freshman, so I have yet to see as many teams as most of you. I have followed High School scores for a while (and most soccer scores, gotta love this game!). As best I can tell, it all comes down to coaching. The schools that have good programs and consistently win have quality coaching.
Every school (public or private) have two or three "great" players, some players with potential, a few average players and then the few that make you scratch your head. The coaches that can put them all together, improve their skills and knowledge, and create soccer players happen to win more games and titles.
Do private schools have an advantage over public in attracting quality coaches? I wouldn't think so. Maybe in some rural areas, but in most of these schools soccer is just an extra activity for the students. (Not dissing, just an observed fact. I have noticed the players still love the game even when losing.)
