For the ages of 11-15 at top clubs (those going to ECNL or whatever), are there just accepted burnout loss percentages of players? It seems like to be competitive at the highest level at the older ages, kids are practicing 3-5 times per week, which seems like it must have some higher risk of burnout than kids practicing 2-3 times. I'm just curious if that's a calculated cost the clubs make (more practices = better teams, but higher burnout) or if they do try to control for that by varying types of practices, having specific multi-week periods off, etc.
At the ECNL level burnout is really just not a thing. Over a decade in I've only seen a couple of kids quite the sport entirely. Some wash out at the "highest levels" but they usually keep playing. Some simply invest their time into another sport or activity that they just happen to prefer. I don't consider that "burn out" as much as changing of priorities and only so much time. What can happen and I have also seen it is when kids with long term injuries simply walk away from the game after rehab or they choose a lower level. Again, not burnout as much as learning that there are other life balances and interests that they were allowed to indulge while being away from the game/team.
I'm not sure it's exactly burnout, but -- purely anecdotally -- the drop off in players around my son at roughly ages 16-18 at the rungs just below those top levels has been pretty high (50 percent or a little more, off the top of my head). I'm thinking about kids across a couple of clubs and on his HS team who had made playing in college a goal and had a realistic shot on some level, right up until they decided they didn't want to chase that any more for whatever reasons.
It seems like players burnout the most at the college level. They work so hard to get that scholarship to any school. Then they realize the school they are at is a poor academic institution, they have little chance to go pro, their coach is riding their ass, all their friends are regular college students having fun at school and they decide to stop playing and transfer to a school that will be best for the next 40 years of their lives.
I agree with the other posters. Actual burnout in boys and girls is mid to late teens. There is a good bit of attrition from 11-12 until then, but there are several other reasons for this.
It seems that so much travel at the top levels would contribute to the burn out more than the daily practices would. I know several people who quit top leagues (MLSNext or ECNL) because of the travel but they still play at high levels and have daily practices--just in leagues that don't travel as much.