Consistency is the only thing that I think any reasonable player/coach/fan asks for from the ump. Once a zone is established, stick with it.
Bottom of 7 last week, ump suddenly stopped calling a certain location vs lefties a strike. Pitcher threw it 3 times in a row, all 3 called a ball. Those of us in the press box were staring at each other with mouths agape when those 3 pitches were called balls.
Next pitch is in just a hair, roped for a single to start the 1-out rally that ultimately won us the game.