My daughter had a soccer coach for years (who now coaches girls DA), who suffered greatly form this.
He taught possession for years in a single-minded focus. Yet, some of the good players he had at U9 weren’t so good at U11 and he couldn’t see it. They got all the playing time and they were turnover machines. So, I tracked possession. Did our team retain or lose possession after a player last touched a ball?
My daughter, who was on the bench, had team best 80% possession numbers. Which is what *I* saw, but he didn’t. His favorite player since U9? 17%. Team worst.
I did this for several games before he finely tuned out his old bias and saw the game for what was actually happening today and not 2 years ago.