I don't really get having challenges instead of just going full-automated. In all sports, I am generally in favor of being able to challenge bad calls, but the actual review process sucks. Having the game pause for the review isn't fun. There are even times when I have wondered if I would rather just go back to no reviews (especially in basketball, or when football first started reviewing every touchdown). But with balls and strikes, I feel like it is the one situation where you can just immediately have the call be correct and we won't have the need for challenges. The thing I'm worried about is the unintended consequences of robo-umps. I'm absolutely deaf ears on "the human element" but some pretty smart people have voiced some valid trepidations about jumping over to the automated strike zone in one fell swoop. - The super-imposed zones on TV aren't actually totally accurate, getting the actual calls takes a little bit of computer processing time - Umps don't actually call the rulebook zone. It's more oval than square, if we jump straight to the rulebook zone what does that do? Or do we want to codify a more practical zone? - Relatedly, the zone expands/contracts based on the count and the score. Does eliminating that all at once break anything? - Does completely eliminating framing do weird/undesirable horsefeathers to the catcher position? We definitely need to move towards automation. But I think an intermediate step is a good idea. Though I 1000% agree it needs to be fast. No sauntering over, putting a headset on, waiting 90 seconds, disseminating the info, etc. Just like flash something on the scoreboard or give the 2B an earpiece and appeal to him a la check swings or something. I don't watch tennis but my understanding is it's pretty quick and painless there? It will undoubtedly take some adjustment but look at tennis. It's not even a thing anymore. All the stuff you mentioned is not relevant.