"In the late 1970s, parents and coaches across the country created "clubs" as an opportunity to get the upper hand. Most school sports last only two or three months, so parents created private clubs to train their kids year-round.
When club players showed up for school sports, they dominated the players who trained for only a few weeks. Other parents saw the skill of club players and quickly enrolled their kids in clubs, too. By the mid-1990s, the best high school athletes in nearly every sport played club.
Now some of the best club soccer coaches in Arizona ban their kids from playing high school sports altogether because they say the competition is beneath them."
I thought the above (from page 2 of the article) was interesting. The Sereno Club routinely wins Arizona and competes extremely well with the Southern California clubs. I'm not in favor of "banning" kids from doing anything, but I would definitely encourage my own children to forego high school soccer if year-round club soccer were an option.