Correction: as a percentage rate by participants, football leads. The gross # for soccer is higher, but the # of participants is also higher by multiples. The concussion rates per participant rates are highest in football, then soccer and then lacrosse. Soccer had been #1 until 4 years ago, but has dampened out. Possibly because the growth rate of soccer continues to be huge and injuries relative to it are down, and that is possibly because of age based teams. But it was recent enough that soccer moved to age based that again there is no real data to back any theory yet.
If there aren't enough players in non-hotbeds to do single year teams, for that same reason there aren't enough players to support 2024, 2023, etc. either. That's a less credible argument, but point taken. I believe this debate is centered on single year grade versus single year age determinations. | 
