I don't know if folks know this or not.
In the conferences where there is technology, balls and strikes are monitored at the plate. The umpires have to maintain a certain % to stay in that conference or for those in training to get the job. Each conference with this availability has their own umpires in conference play that rotate games.
After each game a report goes to the conferences as well as coaches. I don't know if this counts on weekday matchups but does when two different conferences have a weekend series. Standards have to be maintained to keep the job or get it.
I dont know what's standard. I just know there is accountability.
This is why we tend to question why a strike is a ball or ball is a strike.
I am not sure that umpires are not questioned on the report.
That's where the challenge comes in during a game.