Feeder systems COACHED correctly are imperative for a sport that is more of a martial art than a traditional sport and that has very few opportunities in rec leagues for young athletes unlike traditional sports. Back in the 1980's, there were only three teams legitimately competing for state titles: Rock Hill, Summerville, and Irmo. Rock Hill and Summerville had tremendous middle school programs. When Irmo lost their experienced MS coach around 1984, the gap widened. It was only the talent of Irmo's then coach BD LaPrad that kept them in the conversation; although, as a distant third.
In the 90's, LaPrad started the program at Dutch Fork without a real MS program - just a few of his son's friends - and made it to the state finals several times losing to the more balanced teams listed above. I don't think DF started an actual MS team til about 1999, and then it was not as organized or funded as well as the schools feeding RH and the 'Ville,
Looking at this century, several schools that had not won it before can really attribute their success to their feeder system. In one case here in the Midlands a team made a couple finals winning one with a team whose core had been wrestling together since elementary school.