https://theathletic.com/822659/2019/02/18/how-the-mariners-are-using-data-biomechanics-and-technique-to-build-a-better-catcher/
This has been going around, on how with focused PD staff, Seattle is workign to turn a great offensive catcher into a average defensive catcher so you have : a good catcher under control for years.
It's clear after the sox claimed they "revamped" themselves after 2016, that they were ignorant of how needed to be done. I would argue this is because they kept the same people who have been around the same organization for 20 years, but regardless, the mariners are not the forefront of anything but ... look at this.
Now, the sox took a project defensive catcher in the first round, and he will have to become a good mlb catcher without any of the same tools other catchers in other orgs get. This is how you become below average consistently. The margins matter a lot in baseball. Are the best players really 50% better than the worst? Or just 5% better in several areas that allow more consistent success.
The sox are falling down despite the fact that they may be improving when judging themselves to previous practices, because other organizations are improving so rapidly.
Cue Balta and marcus semien and ron washington.