What was mildly irking Cole Hamels?

Cole Hamels had the worst year of his career in 2016. It’s not saying much, as he still surpassed 200 innings pitched, struck out 200 batters, and amassed 3.0 fWAR. Hamels has been worth 3.5-4.9 fWAR in all nine seasons of his career following his rookie season, where he was on pace for the same. Until last year, when Hamels isn’t trying to police the behavior of other adults playing a game, he’s had spectacular control. As much as the Mariners fan in me desperately wants that to be the herald of a trend, I am wary the 33 year-old Hamels still has plenty left in the tank. His struggles last year were not so much tied to loss in velocity as they were in control.

As Jake noted today in his overview of the rotation, his 3.32 ERA masked a 3.98 FIP, and Hamels’ signature control fell off a notch, as his walk rate increased from 7.1% in 2015 to 9.1%. Hamels left pitches up in the zone that he simply did not used to, and it led to an his highest HR/9, 1.08, since 2010. Even considering his home stadium in the warm, hitter-cradling embrace of Arlington, Cole’s 3.85 xFIP was the worst of his career. A look at his pitch usage tells a confusing story.

Fangraphs

For the first time in his career, Hamels’ changeup accounted for less than 1/5^th of his offerings. For his career Hamels has gone with his change over a quarter of the time, and with good reason: it’s been by far his best pitch. In 2016, though, his changeup looked less like Bugs Bunny’s and more like Porky Pig to hitters. Here is a measurement of specific pitch-type value, and, well, ah-C, ah-C, ah-CH stands for change-up, folks.

Fangraphs

Corinne Landrey at Fangraphs pointed out this issue at the start of June. In her article, she remarks that, after missing a start at the end of April due to groin tightness, Hamels began phasing out his changeup in subsequent starts. When he did use the pitch, the results were more erratic. A pitch that Hamels usually painted with became more commonly either spiked or left flat in the zone. A look at his vertical movement below confirms it: Hamels lost nearly a full inch of movement on his bread and butter pitch.

Brooks Baseball

There are a million possible explanations for this and I will not pretend to know what is right. Groin injuries are notoriously prone to linger, and even beyond the physical disruption, they linger in a person’s mind. If you imagined a stabbing pain on your inner thigh every time you stretched too far, you’d be wary of overextension as well. That fear is deadly for pitchers, and is especially detrimental for changeups, which demand the pitcher finish pulling all the way down, fully extended, much like a slider when gripped inversely. Perhaps Hamels has lost the “feel” for his favorite toy, and will continue to show signs of weakness, even as he provides consistency for the thin Rangers rotation. Just as likely, unfortunately, Hamels will spend this offseason healing and working to reunite with his old friend, and 2017 will be another year where the Mariners will have to go through Texas to achieve their playoff dreams.