
Yes, the sport with two names (actually three?). Association football in much of the world. Soccer in the US, Japan, the Phillipines. And both in a few places. Ok, well, this is about coaching the beautiful game. I have an eight year-old and a ten year-old and they are into this and I have to learn more than just play, I need to structure my play with them, include rules, when and how to teach headers (not yet), and other details. So here are my notes:
Youth league divisions
Note that the U signifies on cutoff date (usually July), that the youth is not yet that age. That means my 8 year-old who is under 9, but will be 9, is in the U-9 league (if there was one).
- U-9 to U-10 Junior academy, basic positions and touch
- U-11 to U-12 Intermediate, offside rule and spacing
- U-13 to U-19 Full youth, full tactics and competition
- U-20 to U-23 International youth, elite professional pathway
- U-20 highest true youth level in FIFA
- U-21 regional and European competitions
- U-23 highest age-restricted for Men's olympic football
Header rules and training

This is data from the FA website, though it is somewhat different from the US guidance, it is fairly similar. Ball size and weight makes a difference as well as number of headers in practice and the frequency of that practice.