I agree entirely. Baseball is about the accumulation of (very) small advantages. No umpire is being unfair (whatever particular fans may think about certain ump

I agree entirely. Baseball is about the accumulation of (very) small advantages. No umpire is being unfair (whatever particular fans may think about certain umpires - though, yes, some are better than others), but each umpire is unique, and learning and adapting to individual umpires' idiosyncrasies is a dimension across which the best players can distinguish themselves. Removing that flattens the game. I don't hate the challenge system as much as I would an entirely-automated strike zone - and I'll probably appreciate the occasional corrected call, and the game-within-a-game of when to spend your challenges - but it's all of a piece with the general flattening of baseball. The DH, and now the universal DH. Interleague play. Balanced schedules. Three true outcomes hitters. Outlawing certain defensive positioning. Maniacal pursuit of spin-rate. Manfred runners. All of these eliminate elements of the game that made it more interesting - at least from this Old Man's perspective. (As counter-examples: I like the pitch clock, and I'm OK with enlarging the bases; those increase the premium that accrues to specific skills, and heighten the stakes of particular situations. Those are the directions in which positive changes should point.)