What’s happened to Alex Cobb’s splitter?

Earlier today, Jim Turvey noted that Alex Cobb, while pitching successfully so far, is working a different process than he used to. While his split-fingered changeup used to be his go-to putaway pitch, he’s leaned on it much less after returning from Tommy John surgery.

Cobb’s comments suggest that he’s struggled to regain a feel for the pitch, and observers have noted that his splitter doesn’t have the bite it used to, but pitch action is one of the areas we can easily check for ourselves. So let’s check.

Here are all the pitches Alex Cobb threw in 2014:

And here is what he’s thrown so far in 2017:

Uh-oh.

There are a couple things I’d like you to ignore in this graph:

• Ignore the fact that all of the pitch movements are shifted a bit to the right-handed-batter’s side of the box (left on these graphs). This year, the publicly-available data just switched over from PITCHf/x (cameras) to Trackman (radar), and many things look a little bit different. I’m not all the way through studying it, but preliminarily, at least for the Rays, all pitch movements seem to be shifted left a tad.
• Ignore the four-seam fastball/two-seam fastball classifications. Those are hard to do algorithmically, and with the shift in data the MLBAM classifications have changed.(gotten worse? or just different? not sure. but not good for comparisons across years.)

But one thing which you should not ignore, and which it’s pretty hard to miss, is that Alex Cobb’s splitter no longer drops.

Here’s a look just at the vertical movement of Cobb’s pitches over time.

Cobb’s splitter used to be nasty pitch that fell off the table. Cobb has talked in the past about using it as other pitchers might use a sinking fastball—pounding the bottom of the zone with his best offering to set up other pitches. Now the pitch looks like a straight changeup that relies on tricking batters with the change-of-speed.

And oh, by the way, it might only have 4 mph of speed differential.

Alex Cobb and Jim Hickey are smart men. They understand pitching as well as anyone. But right now they’ve got a problem to solve. Cobb’s best pitch, which used to be a big part of what made him an ace, is no longer special. Maybe they can make it special again. Maybe they can learn to thrive without it.

But I think they need to hurry up and solve their problem quick, because major league batters, hitting coaches, and advance scouts are freakishly good, and the league is watching.