I know Epstein can be learned quickly. IMO the mechanics Mike teaches are not what I see looking at video of MLB hitters. I don't wish to step on the happy times and success you and your daughter have enjoyed with Mike's stuff and that success does not surprise me at all. IMO if you were facing good gold pitching you would find some holes in Mike's approach but short of that, so what? She is having a big time in her pursuits and that's all that matters.