More Umpire Graphs…
After asking the fine folks at Athletics Nation for their opinion of what I’d done with umpire stats, I went back to work.
For all things, it’s beneficial to establish a perspective or a track record. You have to know what you’re looking at before you try and analyze it. In this case, I needed to figure out how consistent umpires have been over the years.
I compiled the stats for all umpires from 1995-2006, and pulled out a dozen who had worked enough games each year to make the stats significant.
There’s some difficulty in working with the stats from Baseball Prospectus, I should add, because the ID assigned to each umpire is inconsistent. It changed after 1998 and again in 2003, and there are rampant misspellings of umpires names.
PLEASE IGNORE ALL DATA FROM 1998. BP’s IDs are so horribly messed up I can’t make sense of that year. For example, for John Hirschbeck, they have a couple games under each of these IDs: Hirscbeck, Hirsch, Hirschbeck, Hirshbeck, J. Hirschbeck, and John Hirschbeck. I don’t know if there’s overlapping data or not, so just pretend 1998 isn’t in the graphs. Sorry.
If I can somehow clean up the rest of this data and get it assigned to the correct umpire, I’ll be able to demonstrate broader trends, but until then, we’ll just have to get by with what I can pull out of it.
This graph isn’t the best in the world. It’s cluttered and a bit confusing. However, it’s the best I can do with the data I have, and the software I have to work with.
Though cluttered, you can see that Deryl Cousins has consistently called a lower percentage of strikes, while Angel Hernandez and John Hirschbeck call a higher percentage.
It’s very interesting to notice that with introduction of QuesTec, an umpire grading system, in 2001 there was a closing of the gap between umpires. In 1995, you can see that the way the strike zone was called varied widely, while in the last few years, most umpires call about the same percentage of strikes.
Also, as you can see, there’s been (at least among these dozen umps) an upward trend in the percentage of pitches that have been called strikes. There was some talk, among pitchers and baseball insiders, that umpires were calling more strikes because they didn’t want to grade poorly on QuesTec. There was also rumor of umpires calling more balls, which is what led Curt Schilling to infamously take a bat to one of the units a few years back.
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Here’s a second graph, showing the umpires’ S0/9 rates over the years:
Again, you can see that Deryl Cousins has had one of the lowest SO/9 ratios since 1995, while Brian Gorman has one of the highest.
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And one more, showing their BB/9 rates since 1995:
Deryl Cousins walked a lot of people, while Angel Hernandez earned his reputation as having a happy right arm.
