I agree, I was only addressing one way, not every way that K can influence BABIP or how they might track based on swing/mechanics.
I don't really believe that a majority of what we saw from Hiura and Yelich from 2019 to 2020 is do to external factors (i.e. a huge change across every opponent in how they pitch to both). I think for some reason there was a decision to change them in some way to get better outcomes or that they both thought 10 is great, let me crank this up to 11 and see what happens. I'm old school with players in that you don't fix what AIN'T broken. Go with what you are successful and adjust when you aren't going as good. I think there's way to much of the Mike Pettine school of thinking (and he wasn't the first, he's just a familiar example) where you coach to a scheme (launch angle) instead of coaching to the talent you have. [Rant] My god, when you know that a run team is the biggest hole in your scheme you should be able to come up with an adjustment to your blessed scheme to reduce the bleeding!!!!! [/rant] These guys have gone through years of development before they are even drafted working on what is the best approach for them. For some there are clearly issues that can be addressed, but I think there's less fine tuning as complete recreating going on. It's crazy that they are compared to a fictitious better hitter/pitcher and then coerced, forced, induced to change so that they fit that other mold. Launch angle, launch angle blah. A good coach should be working on getting each player to their best optimizing their strengths and minimizing their weaknesses, not put them into a system where they won't thrive and then replacing every player to fit the mold (wasting tons of investment with what you already had), And I'm somewhat incensed by this because to me it's a big part of the reason that baseball is so friggin boring in 2022.