Like These (Baby) Changeups

Whether it’s daily fantasy or dynasty, being able to evaluate a pitcher in a small sample can separate the top from the bottom of your league table. Results — particularly balls in play, but really any results that depend on the outcome of a plate appearance — can only go so far. Per-pitch metrics help, since there are four pitches per plate appearance on average, but if you’re talking results, you’re still cutting your sample into those moments when a player swung or put the ball in play.

And then there’s movement and velocity. We know, for example, that it takes only three starts to reliably predict fastball velocity the rest of the way, and that one start actually gives us a good idea. So maybe movements and velocities can help us evaluate young starters quickly.

Let’s find some good young changeups that haven’t established themselves yet. First, here are the movements and speed differences (measured against the fastball) of your average changeups, lefty and righty.

throws	pfx_x	pfx_z	velo diff
righty	-6.5	4.3	8.4
lefty	8.9	5.1	8.5

Looks like lefties throw more frisbees, while righties throw changeups with more drop. The velocity difference is the same, but lefties start with about a mph less, so lefty changes are slower.

So let’s sort by these different aspects of changeups to find some small sample standouts. From Harry Pavlidis’ work, we know that velocity gap is important for whiffs, and that tilt (drop) and fade (run) are important for any change.

Let’s throw out a list of the best small-sample changeups by a few metrics, and then we’ll write about the players. Basically, these changeups all look above-average by movement and velocity, and those aspects probably stabilize pretty quickly. After all, we’re just asking ‘what does it look like, how repeatable is it, and how good are our systems at capturing those aspects?’ Not anything about how the batter perceives the pitch, for example, or what happens when the ball is put into play.

Pitcher	X Move	Y Move	Velo Diff	# Pitches	swSTR%
Andrew Heaney	10.8	4.3	8.6	57	10.5%
Marco Gonzales	9.7	5.4	10.9	156	25.0%
Shane Greene	-9.5	3.5	6.5	41	26.8%
David Buchanan	-9.4	4.6	8.7	383	20.1%
Anthony DeSclafani	-9.4	2.5	7.4	16	12.5%
Blake Treinen	-8.8	2.1	9.0	13	15.4%
Nicholas Tropeano	-8.7	5.1	9.3	78	12.8%
Buck Farmer	-7.4	-0.2	8.6	49	16.3%
Taijuan Walker	-5.8	1.7	7.7	19	10.5%
Jesse Hahn	-6.7	2.8	7.4	77	6.5%
Zach McAllister	-9.1	2.8	12.0	106	5.7%
Odrisamer Despaigne	-3.1	6.2	16.3	169	10.1%
Carlos Martinez	-4.4	4.5	9.5	40	17.5%

You might recognize some of these names from my pitcher rankings.

Andrew Heaney, in particular. He didn’t throw his changeup much, only 57 times, but when he did, it looked like a strong pitch. Only three lefties had more horizontal movement on their changeups than Heaney last year — Chris Sale, David Price, and Matt Moore. Pretty heady company, especially since he was sandwiched in by Alex Wood on the other side. Compared to lefties, his drop is decent, too, and he’s got above-average difference on his fastball. Considering his sinker, breaking ball, and command are considered his strengths, this is all good news.

I don’t think you needed this table to tell you Marco Gonzales has a sexy changeup. But check out how well Heaney’s stacks up against his until you get to the last category.

Shane Greene pretty much picked up his changeup last year, or so goes Brandon McCarthy’s version of events at least. Shane Greene had more horizontal movement than any righty starter (minimum five starts) not named Daisuke Matsuzaka, Chase Anderson, Jake Arrieta, Chris Bassitt or Joe Kelly. Not quite the group of lefty changes from above, but it’s still impressive. By movement, Greene’s change above average in both ways. If he can either deaden the pitch or firm it up velocity wise, it could become a great weapon to pair with his big fastball and two breaking balls.

David Buchanan is the righty Marco Gonzalez is a way — all changeup, no fastball — and he’s thrown more changes than anyone in the sample. But he’s on the list, if just for comparison. (And actually with just a bit more out of his third pitch, and some backwards pitching, he could be a good pitcher this year.)

Because Anthony DeSclafani’s change stacks up well against Buchanan’s, at least until the last category. DeSclafani got top-ten horizontal movement on his change last year. He also had two inches more drop than your average righty change. Let’s see if he can do anything about the velocity difference, but it’s got good movement.

Blake Treinen has what it takes by this analysis. He doesn’t show up in the top ten in either movement bucket, but he does have above-average numbers in both departments, and above-average velocity gap. That’s impressive considering his sinker is almost unique and his breaking ball is generally considered his best secondary pitch.

Buck Farmer and Nicholas Tropeano aren’t getting a lot of love as sleepers, but they’re both probably sixth on their team depth charts — a position that does get use, if not a full share of the work — and they both have decent looking changeups. Buck Farmer‘s change dropped more than anyone other than Charlie Morton’s, more even than third place Felix Hernandez. Tropeano’s change is a bit of a frisbee with below-average drop, but it has a good velocity gap along with those two inches of extra horizontal movement.

Taijuan Walker has been killing it this spring, and added a new breaking ball. His change has a lot of drop, but is a bit straight and has a below-average velocity gap. Maybe curve/slider/fastball will be enough for him.

Jesse Hahn’s change has average fade, two inches of above-average drop, and below-average velocity. I’d call that an average change in sum, which should have an 11-13% whiff rate. If he can get those results from his change, his awesome breaking ball and good velocity will make him an SP2 or 3 in fantasy this year, most likely. The park will help.

Zach McAllister is a dark horse to make the rotation in Cleveland, and he’s been long known as a fastball-only guy. But his changeup is above-average in every way save results. Strange!

We already knew that nobody has a change like Odrisamer Despaigne from a movement perspective. Now know that no starter has a larger gap between the fastball and changeup velocities like Despaigne. And he has this grip on his slow curve. Baseball’s ‘Brow, take a bow.

The last pitcher on our list has below-average movement on his changeup in both directions. So why did we include Carlos Martinez? Because he has a near ten mph gap in velocity with his fastball, and his breaking ball and fastball are established as great pitches. Maybe he can make it work.

These pitchers threw their changeups less than 100 times on average, and yet we might know something about the quality of their platoon-busting pitch. Particularly in the case of Andrew Heaney, Marco Gonzalez, David Buchanan, Blake Treinen, Buck Farmer, and Zach McAllister, we know these changeups are above-average in all the ways that count in samples as small as these.