No correlation at all. Crockett County has had some junior high and freshmen teams with terrible records, but 10 straight years in the playoffs speaks for itself.
A lot of it, IMHO, is philosophy. I know that Crockett County has always rotated a lot of players in and out, not necessarily playing the 12-14 best players and always going for the win. Often times, 5 or 6 running backs may touch the ball every game as 8th graders, but all but 2 or 3 of the best have dropped out of football by the time they reach high school.
At the same time, these kids are learning the high school system and the high school way of doing things, so by the time they reach the high school level they already have a feel of what is expected from them.