Over the course of a season, the bad calls are going to even out. They are bad for everybody.
That said, the quality of the ump's work is pretty poor. There is simply to much variation between the way umps make particular calls, the method they use, the senses they rely on, one to the next and that is just for calls out on the base paths.
When you get to home plate, the variation between where umps position themselves behind the catcher is all over the place. As a consequence their view of the strike zone is different one to the next. I actually think that is a big part of the reason why one guy sees low strikes better than another guy who might see high strikes better and why some see the outer edge better than others.
You have guys that really put themselves over the catcher's shoulder between the batter and catcher. The more they position themselves that way the less they see of the outer edge of the plate. In some cases I don't understand how they are actually seeing the pitch in relation to the outer edge of the plate. They are so far over the inside edge and have gotten so low in relation to the catcher that they would have to look through the catcher to get an actual view of the outer edge. You would prefer that their point of reference for that imaginary box be the actual outer edge of the plate but all to often it is a point in space that they believe to be correct but that is not actually the edge of the plate. In fact I think that is why for some umps the damn things moves farther and farther outside as the game progresses.
It is tough to force yourself to watch how umps do their business behind the plate but if you force yourself to try to get a bead on it, you see some guys that appear to be better positioned to begin with making subtle adjustments to individual pitches as the pitch is on the way and I think they tend to be the better umps as far as balls and strikes are concerned. There are really very very subtle adjustments in their shoulders, neck and head so they are really hard to pick up. The umps that have really got themselves positioned over the inside edge can't make subtle adjustments. They are stuck there like some sort of statue cause you would have to move to far to improve your view and will block yourself or catch yourself completely out of position in some instances or would be moving to much yourself as the pitch is coming in making your movement just another variable.
I don't know if you guys remember the game but there has been an ump this year that did an even worse job of identifying the outer edge of the plate than the guy today. That guy was eventually calling balls that were a full 6" outside the black as strikes. But as bad as all that sounds, there is still the added element of individual thinking that goes into what an ump decides to use for a strike zone.
Some umps think that pitchers should be forced to get the ball up in the hitters wheelhouse a bit more. Others want to reward the pitcher for the low strike. It is ridiculous. Yet just as Stern does nothing about the variety of techniques in the NBA, Uncle Bud does nothing about it in MLB.
I would start by demanding that all umps position themselves behind the catcher exactly the same way. I am sick and tired of guys getting to position themselves where they are "comfortable". I don't care how comfortable they are. If they cannot call balls and strikes from the same place behind the catcher then get umps that can. Sure some of this has to do with the variation between how catchers catch but the catcher is still stuck for the most part in a defined area and regardless of how tall he might be, he is still in a crouch. Once you have forced umps to position themselves the same way regardless of their individual physical differences (height for example) MLB should be able to instruct their umps how they want balls and strikes called. We would go from a system that whether MLB wants to admit it or not is totally subjective to a system that would be structured and managed.
I do wish the players would stop allowing these umps to get under their skins to such a degree because they are defeating themselves. They lose focus and concentration and they are lost at that point.