[mrr54]

Are teams not based on age in the United States? In New Zealand they're all categorised as 'under 9s', 'under 8s', 'under 7s' etc. They've also introduced weight classes to a lot of teen sports too to prevent them from being dominated by gigantic Samoan kids.

[bluGill]

School teams are classed by grade level. Non-school teams are by age. Non-school teams are generally seen as a fun thing to do on weekends, while school teams can become very serious. Hold your kid back early and they will be the star of the team 12 years latter. Some of this is because at some critical points their body is physically better than their peers and thus they get to play a little more and get that much more practice. Some of it is the parents who think doing well in sports is important are teaching their kids young to play sports and so those kids are getting practice at home that other kids do not get.

[animal531]

Yeah, it's a common thing for all sportsmen and women. https://www.sciencenewsforstudents.org/article/why-many-olym...

The positive feedback loop they're in pushes them more and more towards the things they're better at than their peers.