...As for Garver, some of those pitches he pulled six inches were insulting to an umpire. The old "if that was a strike why do you jerk it that far"? come to mind. And yes, after you do that it diminishes your more fluent efforts.
Let me try to drive this home because the concept seems to be still lost on many...
I know this seems counter-intuitive, but manipulating the glove-ball is what lands more catchers strike calls at the bottom/top of the zone. This has been proven in practice at the MLB level. They lose fewer strikes in the zone and they gain more calls outside of the zone. For those in the back: IT DOES NOT DIMINISH THEIR EFFORTS.
To be clear, the low strike glove movement isn't catching and pulling the pitch -- it's working underneath it and up. Watch clips of Max Stassi and Tony Wolters from 2018, two catchers who had some of the higher called strike rates at the bottom of the zone.
Catchers are constantly working in motion. They are not going to nab 6 inches outside and pull it in, but they are going to keep moving as such. The second example in the Garver clip was a breaking ball two-three inches outside that he got called a strike working back over. In slow motion it looks absurd but at game speed, with all of Garver's constant movement, it seems natural in that context.
Data has shown that there is a distinct like where umpires make about 98% correct calls in the zone and out of the zone. There is air space between those two areas that is up for battle right now. Catcher who have implemented this technique have seen greater success rates in that area.
If robo/computer umpires are ever installed things will certainly change, and Swanson acknowledged as such. The focus will change to maximize the best returns from the new system too -- whether it is blocking, throwing, game-calling, whatever can be maximized to the team's advantage.
One thing we talked about how different the game might actually shift with a robo umpire calling a 3D strike zone. Most human umpires call a zone in a 2D capacity. That could change how pitchers attack hitters. One example was if a team felt they feel they could get away with high breaking balls that nip the very top back of the strike zone behind the batter (suggesting the hitter is up in the box), some team is going to exploit that. Do you get even more defensive two-strike swings and even more strike outs because hitters are protecting against some pitches that clip the very back corner. There could be other byproducts of that system no one has even considered yet. It's clear that there will be a lot of eyes on the Atlantic League's experiment this year.