I'm not talking about the change in his role. Sure, his time as White Sox closer was an unmitigated disaster due to circumstances in and beyond his control, but the explanations behind the failures weren't really explored, aside from the perceived absence of "closer mentality."
What I am talking about is the changeup, which might have been an accomplice to those early-season crimes. A pitch that Thornton hadn't thrown in two years resurfaced at odd times and places, and when it disappeared, so did his massive struggles.
I'd been thinking about Thornton since he appeared on White Sox Weekly on Saturday (unavailable on The Score's website at the moment). Thornton summed up his season to Chris Rongey by saying he was the same ol' Easy Heat for the final five months, but the first month couldn't have been much worse, as we are all too well aware.
Thornton is being a little charitable to himself, because he wasn't that great in May, either. His ERA came down, but his execution remained shaky, which is evident in that month's WHIP (1.61). He actually didn't really resemble his commanding self until June, and it happens to coincide with a dramatic reduction in the usage of his worst pitch.
While FanGraphs says Thornton threw a changeup 5.8 percent of the time, it doesn't quite tell the story of the pitch. Using TexasLeaguers.com to find his changeup frequency month by month, on the other hand...
- April: 10.0 percent
- May: 12.0 percent
- June: 5.9 percent
- July: 2.0 percent
- August: 3.6 percent
- September: 1.0 percent
And it was noticeable. In April, I wrote about how Thornton threw an awful lot of changeups at weird times. Parsing the TexasLeaguers data backs up this theory and then some -- he actually threw his change more to lefties than righties, which is quite backwards. Lefties don't often throw changeups to left-handed hitters. Mark Buehrle and John Danks both have excellent changeups, but they won't throw it that often. That's the underlying concept of Joe Maddon's Danks Theory.
Thornton doesn't have a Buehrle- or Danks-grade changeup. At 90 mph and little movement, his changeup is essentially a Will Ohman fastball. But for some reason, he felt inspired to use that pitch more against lefties than his slider. It's really a head-scratcher.
We can't claim cause-and-effect here, but it's funny that Thornton's numbers much more closely resembled his old self after he went back to the fastball-slider combo:
And if you go back to 2010, when he went 8-for-8 in save situations when called upon to close out games, he didn't throw any changeups.
His perfect record from the prior year is the reason why I don't believe he lacks testicular fortitude for saves. But it's possible that having the defined role might have changed his pitch selection for the worse. Given that he would be called upon in righty-heavy innings on purpose, it might have been suggested to him to feature a changeup for the first time in years, and he had neither the tool nor the know-how.
In this scenario, it makes more sense that he might have a minor beef with Don Cooper, as we were pondering. Thornton wouldn't be the pitcher he is today without Don Cooper's help. However, if he was given a bad gameplan that led to the most embarrassing stretch of his career, that might be reason for an airing of grievances. 'Tis the season, after all.
UPDATE (3:26 p.m.): Harry Pavlidis, who knows his way around PITCHf/x, pointed out to me on Twitter that a good chunk of Thornton's changeups were actually misclassified sliders thrown at cutter speed. But he was throwing legit changeups, too, after a prolonged period of going without. In either case, Thornton had this 89-90 mph tweener pitch that didn't do much, and he phased it/them out as the season went on.