How Does the Relative Age Effect Impact Sports Coaching?

Every time I look it up, I'm back in sports, which is really interesting. But it's not bought into the business world or any other world. Malcolm Gladwell spoke about relative age effects 20 years after he first suggested them. And there was loads of research of it now, but it comes from sport. Parents should know this stuff, they just don't, because it's not anywhere in popular media. So annoying.