Yesterday I read that Roy Halladay had changed the grip on his changeup and was throwing it more often (hat tip to Calcaterra on this one). Before this year Halladay held the ball in his palm when throwing a changeup, but during the offseason he worked with pitching coach Rich Dubee and changed to using a split-finger grip. Let’s see whether we can pick up the difference in the pitchf/x data. I think it is clearest in velocity-vertical spin deflection (vertical movement) space.
Definitely a difference: the changeup has about the same velocity but instead of rising about five inches it now drops a couple of inches. The horizontal movement on the pitch is also different.
So the different grip imparts different movement on the pitch, so I think it is fair to say it is a qualitatively different pitch. And Halladay is throwing the pitch more often. As is noted in the article, before 2010 Halladay was pretty much a three-pitch pitcher (cutter, sinker and curve — three great pitches), rarely throwing his change more than 5% of the time. But now he is throwing the change almost 12% of the time. It seems he is much more comfortable with it.
The results show that Halladay has good reason to be more comfortable with the pitch. By our linear weights it is worth 1.5 runs per 100, much better than his changeups in any full year before. Looking at components, the pitch is wildly more successful, getting 19% swinging strikes per pitch in 2010 compared to 6% in 2009-2007 (pitchf/x years). It also gets more ground balls (57% GB/BIP versus 55%) and a lower slugging on contact ( 0.452 bases/contact versus 0.505).
Looking at Halladay’s pitch-count splits, he uses the pitch often when he is ahead in the count. So it looks like he has developed a second out pitch — along with his curve — to put batters away when he is ahead in the count. As Calcaterra noted, it is not like Halladay needed another weapon, but he has one.