How Vance Worley resurrected his career

When the Pirates acquired Vance Worley last year, the Vanimal had just endured a nightmare season. Worley, tabbed as the Twins’ opening day starter in 2013, promptly lost the ability to retire big-league hitters at anything approaching an acceptable rate. After an early-season demotion failed to address his problems, the Twins essentially gave up on the young hurler.

Worley’s arrival in Pittsburgh did not, accordingly, elicit much fanfare. A cursory inspection of Bucs Dugout’s coverage of the Worley acquisition (and the corresponding comments) neatly summarizes the range of sentiments evoked by the new Pirate:

". . . not sure he can help Indianapolis, much less the Pirates."

". . . maybe a reclamation project, maybe a precursor to a bigger trade?"

". . . definitely worth a shot and provides depth at AAA."

Enthusiasm was muted. Worley’s declining velocity, poor strikeout rate, and questionable health all constituted valid reasons to be skeptical. The Pittsburgh pitching staff, however, has become something of an island of misfit toys in recent years, and with each new reclamation project speculation inevitably turns to what sort of Searage-sorcery will transform the struggling pitcher into the next Liriano, Burnett, or Melancon.

It was apropos, then, that Worley performed quite well in 2014, playing a non-insignificant role in the Bucs’ 88-win season. As illustrated below, Worley bounced back admirably to the tune of a 2.85 ERA and 3.44 FIP in 2014.

Outside of his unpleasant 2013, Worley's underlying effectiveness hasn't varied much. His ERA bounces around quite a bit, but he’s pretty consistently been a useful mid- to back-end starter. One could be forgiven for imagining, upon viewing the graph above, that the Pirates’ coaching staff simply helped Worley recapture his 2010-2012 form, perhaps emphasizing the strengths that served as the foundation for his initial success.

This isn't the entire story, however. Worley’s successful 2014 built on many of his early-career strengths, but it also included some novel changes in approach that reflect the Pirates’ broader strategy as an organization. There’s an interesting narrative here surrounding how Worley has been successful in Pittsburgh.

We can start to tell this story by examining the changes in Worley’s peripherals:

We see a certain amount of recovery in Worley’s strikeout and home run rates, but also a profile that is qualitatively different than his early-career self. During 2014, Worley both walked and struck out batters at significantly lower rates than during his 2010-2012 heyday. Always a pitch-to-contact type (I’m going to ignore the obvious Twins jokes here), Worley’s extreme tendencies helped him lead the majors in two interesting categories last season:

Nobody makes people miss less than Vance Worley, especially on pitches out of the strike zone. Not even the immortal Kevin Correia.  Fangraphs’ Jeff Sullivan published an excellent piece last fall detailing both Worley’s extreme bat-finding ability and his league-leading rate of called third strikes, while David Golebiewski addressed the issue more recently. These two attributes make Worley a very unique pitcher. Unfortunately, none of this is new—Worley has always been very hittable, and he’s always relied on deception to retire hitters.

It’s not like Worley’s velocity magically returned, either.

The error bars on PITCHf/x measurements are high enough that the slight variations in velocity since 2012 probably don’t mean much, but you get the picture: when Worley came up, he worked in the low 90s. The last couple years, his velocity’s been a couple MPH lower. If he’s been more effective, it’s not because he’s suddenly found an extra gear.

What did change (rather drastically so) last year was Worley’s BABIP allowed. After increasing every year of his career, it declined over a hundred points between 2013 and 2014, to a not-outrageously-low .299.

We’re left, then, with a pitcher who hasn’t regained his velocity and still doesn’t really miss bats. A pitcher whose peripherals, while slightly altered from his 2010-2012 heyday, don’t exactly scream ‘success story.’ His unique ability to generate called third strikes might explain part of his rebound, but it’s tempting to ascribe much of the resurgence to the giant BABIP fluctuation he’s experienced.  What, then, has actually changed about Vance Worley? Well, a few things:

• Pitch usage
• Contact management
• Release point

First, Worley has changed the composition of his arsenal. Using PITCHf/x data, we can see that Worley’s 2014 marked a drastic shift toward his two-seam fastball, the marginalization of his cutter, and the near-extinction of his changeup.

I’m always a bit worried about over-interpreting PITCHf/x data. Pitch classification is more of an art than a science, and, as Mike Fast noted earlier in the system’s existence, trying to draw conclusions from such a noisy data source can sometimes seem a fool’s errand. That’s why we shouldn’t, for instance, overreact to the sudden existence of a "knuckle curve" in 2014, when previously Worley threw a "curveball." It’s possible that Worley altered his curve; it’s also possible that the pitch was simply reclassified.

But there’s a pretty pronounced change here—Worley came to Pittsburgh and immediately leaned on his two-seam fastball. This isn’t a revolutionary finding—as others have observed, Searage’s emphasis on the two-seam fastball/sinker has been one of the cornerstones of the Pirates’ run-prevention efforts.

Worley’s pitch usage isn’t the whole story, however—he also generates contact in very specific ways, and looking at graphical representations of that contact can help us understand why Worley fits well with the Pirates’ defensive strategy.

This is a heatmap of the balls in play that resulted from Worley’s four-seam fastball in 2013:

And here’s the same heatmap in 2014:

Usually when we talk about whether a pitcher ‘fits’ with the Pirates’ aggressive shifting defense, we focus on groundball frequency. But beyond raw groundball and flyball totals, it’s important to remember that in order for shifts to work, pitchers need to generate groundballs to predictable areas of the field. Between 2013 and 2014, Worley’s use of the four-seam fastball declined quite a bit, but his already-consistent contact management grew even stronger. His four-seam fastball generates a ton of groundballs to the left side of the infield.

His two-seam fastball’s contact distribution is a bit messier. See below for 2013:

And 2014 . . .

We can still see some interesting patterns emerge. The 2013 heatmap is a mess—plenty of hits to the outfield and minimal consistency in the distribution of contact. The two big red dots in deep LCF are particularly problematic. The 2014 heatmap is more positive. Worley’s sinker now generates many groundballs to the middle infielders, and not much down the lines (though the red dot on the left field line is somewhat worrisome). This is important, because the types of groundballs Worley’s generating are much more likely to be outs and double play balls.

Finally, Worley may have ironed out some mechanical problems with his release point. Below, courtesy of TexasLeaguers.com, we can see how Worley’s release point has evolved over the past few years:

The differences over time are subtle, but they’re there. Worley used to have quite a bit of horizontal variation in his release point, and during his nightmare 2013 his release point also drifted inward a bit—possibly indicative of a rising arm slot. Last year, his release point was both more consistent and further outside—the grouping of the dots is tighter and further to the left.

I can’t tell you whether Worley will continue to be effective. He’s exceeded expectations already, and pitchers with his smoke-and-mirrors contact manager profile tend to have a very thin margin for error. Nor can I say with any sort of certainty what Huntington, Benedict, and company look for when scouting buy-low pitchers like Worley.

But I can say that Vance Worley is an outlier. He’s a pitcher unlike any other. And outliers are inherently interesting. They help us understand the front office’s strategy (my guess: Ray Searage space magic), and they show us that different paths exist to achieve success. Hopefully, the Vanimal will keep doing his thing in Pittsburgh for years to come.