It’s not hard to see why the Pirates skipped Charlie Morton’s turn in the rotation yesterday. In his last six starts, his ERA is 5.81 and he’s allowed a whopping 50 hits in 31 innings. With his inning count piling up and an opportunity presented by the Thursday/Monday double offday, it makes plenty of sense to give Morton some time to get back on track. So what do we really know right now? Neal Huntington said on his radio show yesterday that Morton’s fatigue got him out of sync mechanically and that he’s been working with Ray Searage on “tweaks to [his] preparation” to “help him avoid enduring fatigue issues.” That sounds like an awful lot of buzzwords to me, so let’s take a closer look.
First up is peripherals. Morton’s been giving up an awful lot of bloopers and infield hits; how different are the things that we generally accept that a pitcher can control? Because Morton walked five hitters in each of his first two starts and that skews things a bit, let’s toss those out and compare starts 3-8 as one group and 9-14 as a second. Here’s how they compare:
- Starts 2-8: 42 IP, 26 K (5.57 K/9), 16 BB (3.4 BB/9), 1.56 GB/FB ratio, 20% LD
- Starts 9-14: 31 IP, 21 K (6.09 K/9), 9 BB (2.61 BB/9), 1.95 GB/FB raio, 17% LD
So the Morton that’s been getting teed off on in his last six starts is way, way statistically superior than the Morton that shut down the National League from mid-April to mid-May in the categories that most sabermetricians agree that pitchers can directly influence. The biggest difference is that hitters hit .280 on balls in play against Morton in starts 2-8 and they’ve hit a ridiculous .424 on balls in play since, which is something that pitchers have less control over.
Morton’s striking out more hitters, walking fewer, and getting more groundballs. But for some reason those groundballs have eyes. This is weird. We can now make two assumptions: 1.) Either this is epically bad luck for Mr. Morton or 2.) There’s some kind of explanation that exists deeper in what’s happening to Morton. I’m skeptical of option #2. Morton’s early-season success as at least partially lucky because of his sub-optimal K/BB ratio, so now he’s having some bad luck. Happens to everyone. But let’s pretend like there is some kind of mystical explanation here and see if we can find it.
Let’s begin by debunking the rather popular idea that Morton’s struggling because of the injuries to his catchers, Chris Snyder and Ryan Doumit. I hate the idea of catcher’s ERA in the first place and I hate applying it here because it implies that Morton is some kind of porcelain doll that’s so fragile that he can’t handle pitching to a different catcher. The bottom line is that there’s no evidence for catcher’s ERA as a meaningful stat and we should move on.
Huntington seemed to be implying that Morton had some mechanical issues; Morton’s change in mechanics this year are tied to his improved sinker, so if he is having issues with his mechanics, maybe we can notice a change in his pitches. Let’s start with movement (remember, these charts are vertical break vs. horizontal): 
Doesn’t seem like there’s much there. Most of Morton’s pitches the last month have about the same break as his pitches earlier this year. Let’s move on to velocity. 
Sure doesn’t seem like Morton’s fastball/sinker is losing much juice, though it does appear that his slower pitches, meaning changeups and curves) are slightly different. There might be something there; PitchFX is registering some pitches as sliders that it wasn’t before and it may be the changeup. He throws mostly fastballs and sinkers, though, so the offspeed stuff is a relatively small sample size to compare with.
Finally, let’s check release point since Huntington mentioned his mechanics: 
Besides the intentional walks, I don’t think there’s a lot ot see here, either.
It’s really hard to put a finger on what Morton’s been struggling with. His peripherals have actually improved over the last month and I can’t detect much of a change, if any, except maybe in the velocity of some of his off-speed pitches (if any thing, the drop in velocity there is welcome as his changeup wasn’t much different from his fastball early in the season). Everything else seems consistent with what he was doing early in the year.
So is it all bad luck? I’m a little loathe to just write it all off to that at this point, just because the difference has been so dramatic. I do have one other theory that might be applicable there, though it’s pretty much impossible to research prove. Morton’s struggles have really only become pronounced since teams began stacking their lineups with lefties against him. It’s possible that the Pirates shift their infield differently for lefties and they’ve been doing so in a way that creates more soft spots for the seeing-eye grounders/bloopers/infield hits that have killed Morton of late. That’s really the only explanation I can think of beyond epic bad luck. If I were Neal Huntington and Clint Hurdle and Nick Leyva, though, that’s what I’d be studying on the film right now. Obviously I can’t say for sure that that’s cause of Morton’s struggles, but the larger number of lefties faced is definitely a variable that’s not accounted for in any of these charts.
Whatever the cause of Morton’s struggles is, it’s highly unlikely that hitters will continue hitting .424 against him on balls in play and as that number comes down, his ERA will as well. The Pirates aren’t wrong to be careful with his inning count this year, and it doesn’t seem like they’re overreacting and overhauling his mechanics again in response to a few bad starts. In some ways Morton is like a rookie in that he’s dramatically different from last year’s version, so really the only way to figure the guy out is to keep watching him and collecting data points.
