Near the beginning of 2011, Jim Hickey was on record as saying that he prefers his starting pitchers to have four pitches, but that he didn't want to change Jeremy Hellickson's three pitch approach because it was obviously working. Well, one season of a sterling ERA but troubling peripherals (4.78 SIERA), especially against left handed batters, seems to have changed his mind. Reports out of spring training were that Hellickson was introducing a cutter.
It's usually a good idea to be leery of spring training reports. It's also smart to avoid relying on the mlbam pitch classifications to identify a new pitch, as the classifications are continuously being improved, which means that what was classified one way in 2011 could be the same pitch classified differently in 2012. One game in, though, it looks like Helly's rumored cutter is real.
For 2010 and 2011, I've assumed that any pitches straying into cutter territory are errant four seam or two seam fastballs. For 2012, I've assumed the existence of a cutter. Go ahead and take a look for yourself. In only one game in 2012, Hellickson has already thrown more fastballs with 5-10 inches of rise and either positive or only slightly negative run. That's good enough for me.
How will Hellickson use his new pitch? It's way to early to tell from the data, but generally, the cutter is a platoon neutral pitch, so it gives him another useful weapon against left handed hitters. He hasn't varied his pitch mix by handedness dramatically in the past, though, preferring to stay unpredictable, so I'd bet he uses his cutter to both lefties and righties.
Regardless, this is exciting, and it's a reminder that pitchers are not automatons, with results randomly varying around their true talent from season to season. Rather, the pitchers change, and their true talent changes.