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On The Mariners' Catchers Or Pitchers Or Both

Baseball is a very complicated game built from many individual components. Sometimes studying individual components can get you in trouble, because then it emphasizes the individual component, and you think about trying to improve that individual component. We've seen this with Mariners fans who have been clamoring for a big bat for years. The Mariners, obviously, have had a lot of really bad team offenses, and those offenses could've stood to be improved, but the important issue isn't about the individual component of offense. It's about overall value. The Mariners have never needed to add just offensive value - they've needed to add value, however possible, and offense is one way to do that.

But studying individual components can be worthwhile for learning's sake and curiosity's sake, and in this post we look at the individual component of called strikes. This post is based on this other post that I already wrote elsewhere, and here I'm getting Mariners-specific.

FanGraphs provides raw ball/strike/pitch data, and it also provides plate-discipline data based on PITCHfx. That plate-discipline data tells you what rate of pitches have been located within the PITCHfx strike zone, and also the rate of swings at pitches out of the PITCHfx strike zone. With a little wizardry elementary mathematics, we can figure out which pitching staffs have gotten the most and least strikes, relative to how many strikes PITCHfx would expect them to have.

You can see the overall results if you click through to the other post. It's probably the Mariners you're most curious about. Here's the bottom of the team leaderboard:

28. Seattle
29. Pittsburgh
30. Cleveland

The numbers show that the Mariners have gotten 121 fewer strikes than you'd expect based on PITCHfx. Now, the average isn't zero - it's -36, so you could say the Mariners are 85 strikes below average, according to this method.

It isn't perfect. The PITCHfx strike zone and the human strike zone are different. We know that umpires have non-rule-book zones, including strikes outside off the plate to left-handed batters. Additionally, FanGraphs provides Baseball Info Solutions plate-discipline data as well as PITCHfx plate-discipline data, and the BIS data has the Mariners looking better. But I don't trust the BIS data nearly as much as I trust the PITCHfx data, because the PITCHfx data is all automated and therefore pretty much free of human error.

So the Mariners show up towards the bottom. If this is telling us anything meaningful, a part of it could be that the Mariners have some difficult pitchers to judge. Felix Hernandez generates insane movement on most of his pitches, and Brandon League also generates insane movement on most of his pitches, and that can make an umpire's life more tricky. But I think a bigger part of this could be pitch-framing. That the Mariners' catchers haven't done as good a job of selling borderline strikes as most other teams' catchers.

That's something we've anecdotally observed, and these numbers support it. Now, before you go jumping all over Miguel Olivo, Olivo got hurt at the end of April, and I don't see much of a difference in the numbers between April and May. This issue didn't disappear when Olivo went on the disabled list. The evidence so far suggests that Olivo wasn't framing real well, but the evidence suggests Jesus Montero and John Jaso haven't combined to frame real well in Olivo's absence. Not that we'd expect Montero or Jaso to be pitch-framing magicians. There are questions about Montero's long-term potential to catch. The Rays traded Jaso for Josh Lueke, after Josh Lueke had a rough introduction to the Majors.

I want to emphasize that I might not actually be measuring anything significant here. I could stand to have some smarter people weigh in, and a more useful study would be comparing strikes to the number of strikes you'd expect based on the average human strike zone. I don't know if that's what the PITCHfx strike zone captures. There could also be sample-size issues here, or data consistency issues, or other issues that aren't presently coming to mind. PITCHfx treats the strike zone as two-dimensional, where in reality the strike zone is three-dimensional. That's also a thing. Don't just look at these numbers and declare that the Mariners have had baseball's third-worst pitch-framers.

But we've felt like the Mariners' catchers have been bad at framing, and here our feelings are supported. That's not worth everything, but that's not worth nothing. There are some things I'd love for Jesus Montero to learn from Miguel Olivo. There are other things I'm afraid of.