Quick, who’s leading Major League Baseball in unearned runs? You’d probably expect it to be a pitch-to-contact starter who’s thrown a ton of innings and maybe gives up a lot of ground balls. Clayton Richard and Matt Harrison would be good candidates. Jason Vargas or Wandy Rodriguez could fit the bill. Kyle Lohse? Mark Buehrle? Maybe Hiroki Kuroda?
What if I told you that it was Zach McAllister?
Believe it or not, McAllister’s 19 unearned runs allowed rank atop the MLB leaderboards this year despite his ranking tied for 106th in total runs allowed (69). He’s given up more than an unearned run every six innings. That may sound ridiculously esoteric and trivial, I think his obscure supremacy is both interesting and quite telling about what’s driving his inconsistency.
In case it’s not apparent, McAllister doesn’t really fit the profile of a pitcher who would give up a lot of unearned runs. First and foremost, he’s thrown only 108.1 innings this year—that’s good for 141st in the majors and less than half the of the 217.1 frames league leader Justin Verlander has accumulated. Beyond that, McAllister has struck out more than 1 out of every 5 batters he’s faced this year, so batters have fewer opportunities to put the ball in play and induce errors. Plus he’s a flyball pitcher, and MLB fielders are generally more prone to muffing hard ground balls than they are to dropping pop flies.
So where are all these unearned runs coming from? It’s not that the Indians are giving up an unusual number of errors behind him. In 2012, American League teams have given up errors at a rate of about 1.6 miscues per 100 plate appearances; opposing batters have induced 1.9 defensive misplays per 100 PA’s against McAllister. That’s a slight difference, but it’s not enough to explain the incredible number of unearned runs he’s allowed this year.
The roots of McAllister’s quirky supremacy lie in the frequency with which errors lead to runs. The leaguewide average is .59 unearned runs per error allowed, but McAllister has given up 2.1 unearned runs per error this year, more than triple the AL norm. The problem, therefore isn’t that McAllister has given a lot of unearned baserunners—it’s that he’s allowing too many of them to cross the plate.
Anecdotally, this narrative fits in well with what we’ve seen to be McAllister’s Achilles heel this year: his inability to stop a rally before it gets out of hand. You can say this about just about every pitcher in the game, but it applies especially for McAllister. He’ll look downright dominant for a few innings, then two baserunners will reach base and the hits just keep falling. The fact that he’s given up more than 1.3 homers per nine innings doesn’t help either.
In other words, the fact that McAllister is leading all of baseball in unearned runs despite his not fitting the profile of an error-prone pitcher isn’t just an interesting bit of trivia. His struggles to strand runners might just be the product of a small sample size, but even if they are—and that is an if—his lofty unearned runs total is a reflection of his demonstrated inability to nip potential rallies in the bud.
Again, we’re dealing with little more than a half-season’s worth of data for McAllister this year so the sample size isn’t very large, and it doesn’t overshadow the fact that McAllister is a 24-year-old starting pitcher who’s striking out more than eight batters per nine innings. But I don’t think it’s just bad luck that he’s given up more unearned runs than anyone in baseball.