Whether Vance Worley is the Worley Bird or the Vanimal to you, the begoggled Phillies starter has probably surprised you. After years of lackluster strikeout rates and little prospect fanfare in the Minor Leagues, he seemed destined for the Kyle Kendrick role: eating the innings that Joe Blanton was supposed to. Then Worley came up in late 2010 and a meme was born.

The list of September Surprises that turned into Sophomore Suckers is long, but Worley shook off the doubters and put up 130-plus innings of three-ERA ball in 2011. Believers began singing the praises of his command above and beyond his control — he could put the ball where he wanted to in the strike zone.

And yet, going into this year, he still had his doubters. And for good reason. Though his strikeout rate ranked 23rd among the 119 starters with at least 150 innings since the beginning of 2011, his swinging strike rate ranked 116th on that same list. He struck people out like Jon Lester and got whiffs like Kevin Correia.

Where were the strikeouts coming from if not from whiffs? How were fantasy players supposed to trust another back-end Phillie starter with a 90 MPH fastball, a sub-six swinging strike rate, and a mediocre ground-ball rate?

A couple of recent studies seem to have differing opinions on the subject.

Michael Barr, writing for FanGraphs+, a pay portion at FanGraphs, found that swinging strike rate did a fine job of predicting strikeout rate. A better job than strikeout rate itself. And if you add in velocity, you can predict more than three-quarters of next year’s strikeout rate. Here’s the equation he produced, with an r-square of .769 and a standard error of .0209:

xK% = -.278 + (.003)*FBv + (1.428)*SwStr% + (.321)*K% 2010


And if you plug in Worley’s career numbers into this prediction engine, you get a 14.3% expected strikeout rate. Compared to his 22.2% career strikeout rate, that’s a much more modest expectation. In fact, that difference, had it qualified for Barr’s research (he asked for more innings of his starters), would have been the largest gap in his study.

But before we insist that he won’t continue this streak he’s on, we should remember back to a piece by Matt Swartz when he was at Baseball Prospectus. Swartz found that both swinging and called strikeouts are highly correlated with future strikeouts, but that there didn’t seem to be much difference between the two correlations.

Here’s the money shot from Swartz:

In other words, knowing how much of a pitcher’s SO/PA came on swings versus called strikes was not useful at all.

Huh. So we have dueling results here? One says the Vanimal will be caged soon, the other says the Worley Bird can fly free going forward?

Not quite. Ask Eric Seidman, who has written for both sites and for his own Phillies site, Brotherly Glove, says that the two studies can co-exist. “Its almost like saying swinging strikes are more consistent for pitchers from year-to-year, but neither swinging strikeouts nor called strikeouts hold any predictive advantage over the other,” he says.

It can be hard to agree with this intuitively. A pitcher that can make the batter miss has to be superior to the pitcher that depends on the ump for his livelihood, right?

And then, if you look back at all qualified pitchers since 2002 — when swinging strikes were first recorded — the highest strikeout rate for a pitcher with a sub-six swinging strike rate was Doug Fister’s 14.9%. Even if you go to sub-seven, your highest strikeout rate was Brett Anderson’s 18.3% (and Anderson had a 6.9% swinging strike rate compared to Worley’s 5.5%). Worley’s 22.2% strikeout rate still looks like an outlier among the outliers.

This is not to impugn Swartz’s work — he’s forgotten more than I’ve ever learned — but perhaps to call for more research on the subject. His focus on the ‘swinging strikeout’ seems to stick out to me — that’s just the final strike, and there were at least two others that might have come on called or swinging strikes on the way in. That seems relevant, especially in the face of Barr’s work.

In the meantime, it can’t be that wrong for me to go with my intuition and pick the guy with the swing-and-miss stuff over the called strike impresario when all things are equal. In your fantasy league, that probably means making decisions like Jeff Samardzija (12% swSTR%) over Wei-Yin Chen (7.2%), and maybe Kyle Drabek (10.2%) and Drew Smyly (9.4%) over Juan Nicasio (4.8%) — even if it’s a little early to be definitive and there are other variables at play in each of these cases (especially velocity, which was part of Barr’s work in particular). It just doesn’t seem safe to build a fantasy strategy out of Worley’s work to date.

Worley just seems like such a rare bird, after all.

Comments (7)

  1. It’s nice to use all the fancy numbers to make predictions. But sometimes it’s necessary to actually watch people pitch in order to figure out what going on with numbers that don’t agree with models. Remember that models are imperfect by nature and can not predict anything with 100% reliability. In the cases of Nicasio and Worley, both of whom I’ve seen pitch a number of times its a pretty simple explanation. Both guys have OK stuff but pinpoint location. Worley in particular is one of the best guys I’ve ever seen at locating his backdoor slider/cutter. That’s the type of pitch guys won’t typically swing at but that will generate a lot of called strikes, hence the outlying statistics. Nocasio has great command too, he doesn’t get many swinging strikes becuase his fastball is very straight, but he locate low and away almost every time, which generates alot of called strikes as well.

  2. Sorry for all the spelling mistakes, I’m a little too hopped up on my afternoon coffee.

  3. I’ve always thought of C.J. Wilson as a lesser pitcher because of his lack of swinging strikes.It’s such a bias, I didn’t even consider that there might be skill in collecting called strikes.

    • I bet it’s one of those things you want to see for a long time to believe though. Much easier to see a guy has swing and miss stuff in the swSTR%, easier to believe at beginning of career. If a guy doesn’t have swing and miss stuff, he has to either generate grounders by the bushel, or in this case, locate within the zone. it’s amazing that Worley’s walk rate is basically league average even with this ability, if he has it.

      • Pretty intersting, I didn’t realize that his walk rate was pretty average. Could be for two reason’s in my mind 1. either he throws a ton of breaking pitches compared to average (not sure where to find that data) or 2. (and I think this is more likely from what I remember from seeing his starts) is that he relies a lot on nibbling and throwing things like backdoor sliders etc. which if you hit you spot are good pitches but are more likely to miss then just tossing a fastball low.

        • He does throw more sliders than usual. He’s almost a two-pitch guy with fastball at 67% and slider at 25%. That’s actually a ton of sliders… but sliders are supposed to get whiffs! More than fastballs at least. He confounds me.

  4. I’m telling you it’s the backdoor sliders Eno….he’s the master

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