|I haven't the slightest notion of|
what Tyler Duffey's doing here.
I am trying to be sanguine about this. As I've said in recent posts, the Twins (and virtually every other team) will use about eight starting pitchers in the coming season. Duffey will almost certainly be one of them even if he doesn't open the season in Minnesota.
But to the extent that Duffey lost the rotation spot that he had been penciled in for because he was trying to develop his changeup -- as opposed to, perhaps, pitching poorly as the result of his workload increase last season -- well, that's irritating because it probably wasn't necessary.
The pitching repertoire lists show Duffey as a two-pitch pitcher. The Bill James Handbook says Duffey threw 58 percent fastballs last year with the Twins, 40 percent curves, 2 percent changes. By all accounts, Duffey put the change "in his back pocket" down the stretch.
But ... he throws two fastballs and two curves, as detailed in this Fangraphs piece. (The piece was posted Tuesday just before Duffey's demotion was announced.) Duffey throws both the two-seam fastball (aka sinker) and the four-seam fastball. And he throws two distinct types of curves, with different speeds and "shapes."
That's four pitches, not two. Now, there is an oddity about the fastballs; Most two-fastball pitchers get noticeably greater velocity out of their four-seamer than from their two-seamer. Duffey says his are about the same speed. So maybe the fastballs would more accurately count as 1.5, but he clearly thinks of them as different pitches. One moves, the other does not.
Anyway, the change would be a fifth pitch, and there comes a point for any pitcher when the repertoire becomes too large.
Neil Allen, the Twins pitching coach, believes strongly in the changeup, and for most pitchers that's legitimate. Duffey himself in the Fangraphs piece sounds convinced that he'll need an effective changeup. I'm not so sure. I'm afraid the push for a change is fixing something that wasn't broken, until they broke it.