Missing: Kyle Drabek’s Curveball

During last year’s Double A Eastern League playoffs, Keith Law wrote of Kyle Drabek:

His power curveball at 84-86 was a big league out pitch, with depth and a very sharp break — and he threw it for strikes in addition to burying it for swings and misses.

For a fan base that’s constantly searching for validation, Law’s endorsement of the Blue Jays’ number one prospect was received with the jubilation normally reserved for a home run off the bat of a certain right fielder in Toronto. If Drabek was the bonafide prospect that pundits were suggesting, the Roy Halladay trade might not have been as garment rending as it first seemed. Perhaps management’s number one priority wasn’t trying to ruin the baseball club after all. And maybe, just maybe, the Toronto Blue Jays would eventually find themselves in the playoffs once again.

Several months later, Drabek has cemented his status as a member of the Blue Jays rotation. While he’s certainly struggled to locate the strike zone from time to time, Drabek’s difficulties have been brushed aside as little more than the process that a young pitcher goes through to find his Major League legs.

Following his last start against the Detroit Tigers, a frequent commenter on Getting Blanked noted in the game summary that Drabek didn’t use his curveball once in the game. I did a little more digging and discovered that according to the Pitch FX numbers used by TexasLeaguers.com, Drabek hadn’t used his curveball since April 25th.

For a hook that was supposed to be his Major League out pitch, it seemed strange that it would be abandoned over his last three starts. My first thought was that something was wrong with his fingers. I remembered noticing that Drabek was looking at his right hand immediately after throwing pitches during his last outing and it was even mentioned during the first inning of the telecast. Could blisters or a cut on his hand be affecting the way he pitched?

Aside: Pay no mind to the radar readings on Rogers Sportsnet’s Blue Jays broadcasts. The numbers’ reliability lays somewhere between a politician’s and a Bob Elliott’s unnamed NL scout’s.

However, I think that the hand thing was a bit of a red herring. When one digs deeper into his pitches through Pitch FX, it reveals that the apparent loss of his curveball wasn’t the only change that occurred three starts ago. He also began throwing a slider again.

Many pitchers use the same grip for both a curveball and slider, but typically, a slider moves more horizontally while a curve has more of a vertical drop. Also, pitchers who throw over the top will often use a curve, while guys throwing from a three quarter arm slot are more likely to utilize a slider.

Now, this wouldn’t be the first time that Pitch FX has mislabeled a pitch, and both pitches have similar velocities, but adding an element of mystery to Drabek’s pitch selection is that when he was first called up to the Major Leagues after the Eastern League playoffs that Law described, he was throwing both a curveball and a slider.

Here is the plotting for his curveball’s velocity versus spin angle during his first three Major League starts.

First, the curve:

And the slider:

The lower spin angle would make for a more tumbling, traditional 12-6 curveball. For example, the spin angle on A.J. Burnett’s knuckle curve this season has averaged 44 degrees. For Drabek in his first three starts, pitches classified as a curveball averaged 43 degrees, while pitches classified as a slider averaged 156 degrees. You can also tell that there’s a difference between the two pitches by looking at the actual spin rate. For Drabek’s curveball, Pitch FX says that the average spin rate 1,469 rpm (Burnett’s 12-6 knuckle curve is 1,462), while his slider turns over 641 times in a minute.

Now, let’s go to his first five starts of this season, and look at what Pitch FX labels as his curveball.

More than half of his supposed curveballs have a completely different spin angle from the curveball he threw before the start of 2011, and his average spin rate drops from 1,469 rpms to 1,255. But if you look a bit closer to his plotted pitches, you’ll notice that the ones past the 210 degrees mark are significantly faster than the ones below the 60 degrees mark. In fact, their speed matches quite well with Drabek’s changeup, which also matches the spin angle too.

And now here are his last four starts, taking a look at what’s labelled as his slider:

There appear to be a lot of pitches that are consistent with his curveball in that 80-85 mph range with spin angle of less than 60 degrees.

My theory, and take this with a grain of salt because I’m far from an expert on these matters, is that if Drabek has dropped anything from last year at all it’s actually his slider. What are being recognized as sliders in his last four starts are actually curveballs, failed curveballs and failed changeups. Prior to those starts, his changeups, which have a larger than average vertical drop, were being misidentified as curve balls. This would also explain why in his first five starts of the year, he’s recorded as only throwing a changeup 1.8% of the time, while in his last four, it’s been bumped to 13.1%.

While he hasn’t completely dropped the curve as the Pitch FX charts suggest, he is using it a lot less. In fact, it’s the least used pitch in his entire arsenal which includes a four seamer, a two seamer, a cut fastball, and the two or three pitches we’ve been talking about here.

I’m sure that manager John Farrell and pitching coach Bruce Walton know best, but I’d be curious to understand the reasoning behind Drabek’s increased use of the changeup seemingly at the expense of his curve, which is the pitch that we heard such great things about while Drabek was a prospect.

At the very least, looking at all of his pitches allows us to mock what former Washington Nationals GM Jim Bowden recently said about Drabek:

Drabek has the competitiveness of his mom, the poise of his dad, and the athelticism of both. His velocity improved after the Tommy John surgery; he’s now throwing in the mid-90s with a wipe-out, spiked curveball and a developing changeup.

That “developing” changeup is actually being thrown a whole lot more than the “wipe-out, spiked” curveball of Drabek’s reputation.