A Few More Words on Rob Whalen and Pitch Terminology
Rob Whalen is one of two starting pitcher prospects the M’s picked up from Atlanta in exchange for Alex Jackson, and given his size, stuff, and results in his first big league trial with the Braves, I kind of skipped over him in my write-up of the trade to get to Max Povse. Povse is 6’8″, and while his fastball velo has been all over the map, it’s at least touched the mid-90s, something Whalen is probably not going to do. That said, I think I may have skipped over Whalen a bit too quickly.
Whalen’s minor league track record is more encouraging, in that he’s consistently posted great runs-allowed numbers despite a good-but-not-great FIP thanks to low BABIPs. It’s generally a fool’s errand to count on something like that long term, and even though he had a low BABIP with the Braves, it didn’t prevent him from getting knocked around. The story’s somewhat similar for the guy I saw/still see as his best comparison, albeit purely from a pitch fx/pitch movement standpoint: former Dodger Stephen Fife. But when I mentioned Whalen’s 90mph fastball, I mentioned another, better, comp: “Purely on movement, his four seam looks like Garrett Richards’, though of course Richards adds about 7-8 MPH to the mix.” How does this change how we might see Whalen, particularly given the huge gap in velocity between the two odd fastballs?
Back in 2015, I geeked out about Garrett Richards’ spin in this game post before he faced off against Felix and the M’s. As Alan Nathan’s baseball physics lessons teach us, there are two kinds of spin a pitcher can impart to the ball. One, the one we generally care about, is transverse spin, which is what causes the pitch to move. A fourseam fastball from Chris Young or Yu Darvish has a ton of backspin, meaning that the ball is spinning around an axis perpendicular to the direction the pitch is going. In this case, that spin causes turbulence behind the ball, and the magnus force pushes the fastball up (Ok, technically, it just resists gravity more than a non-spinning pitch would). This backspin produces the big “rise” or vertical movement you see from pitchers, and these rising FBs generally induce more swinging strikes. The other type of spin, gyro spin, is on an axis parallel to the direction of travel: this is akin to a spiral in football. The quarterback isn’t throwing a spiral to cause the ball to move – he’s throwing a spiral so that it DOES NOT deviate from its course. Gyro spin in a baseball produces *no movement* compared to a ball thrown without spin.
If you measure a pitch’s spin based on that pitch’s movement – and that’s exactly how pitch FX does it (it imputes spin from trajectory, so it’s *only* picking up transverse spin) – then you’ll find that fastballs move like crazy, while some breaking balls, particularly sliders, don’t “move” at all. Trackman’s cameras can actually measure spin directly instead of deriving it from other data, so it’s an entirely different measure, one that includes *both* transverse and gyro spin. In general, as Alan Nathan found, fastballs have a higher proportion of transverse spin (again, think of a rising fastball), and thus the measures of spin on fastballs in pitch fx and trackman are closer than they are for sliders and curves.
But not for Garrett Richards. Pull up a pitch fx view of his fastball, like this one, and you’ll see a pitcher with a *low* spin fastball – well under 2,000 RPM – but a higher (2100) rate on his curve. Ask Trackman/Statcast, and the picture’s very, very different: Garrett Richards is the high-spin poster boy. His four-seam fastball, the one pitch fx shows as spinning very little, is a wonder in Statcast, spinning 2,500 times per minute. That’s a huge, huge discrepancy, and the only explanation is that there’s a lot – an absolute ton – of gyro spin on his fastball.
Eric Longenhagen’s scouting report on Whalen is a lot like mine – 90mph, scuffled with Atlanta, may be a reliever or swingman. But buried at the end was a note about Whalen’s exceptional spin rates, measured at 2,400RPMs. I pulled up Baseballsavant, and it’s true: Whalen’s FB spins like crazy, it just isn’t generating any movement, just like Richards’. But why would you *want* that? If high transverse spin creates movement (and whiffs), then isn’t that better than this useless gyro stuff? Maybe not.
Years ago, Max Marchi set out to categorize pitches and how batters reacted to them with pitch FX. Instead of using the standard pitch types, or what MLBAM classified them as (or even what the pitchers *themselves* called them), he made his own categories based on how they moved. In the end, he came up with *17* categories, separating “jumping” fastballs (think Chris Young) from “riding” fastballs (think Sean Manaea now, or old school Randy Johnson). This debate about where the boundary between a slider and a cutter or a fastball and a cutter is keeps popping up, and it’s something I’ve mentioned here before. Anyway, if you click the link to Max’s work, his “cutter” bin had an average horizontal movement of -0.4″ with vertical movement of 6.6″. Garrett Richards’ “four seam” last year had average horizontal movement of -0.4″ with vertical movement of 6.9″. Rob Whalen’s “four seam” last year averaged -0.2″ and 6.5″, respectively. There are two things I take from this: first, Whalen and Richards’ four-seamers are actually cutters, and second, a handy definition for *this sort of cutter* (not those way over on the slider end) is a fastball thrown with gyro spin. They spin like mad, but don’t move like mad.
Ok, ok, so again, why does that matter? Why should we care more if we call them cutters versus four-seamers versus shplankoids? Because batters have a bit more trouble with cutters – their movement may be part of the reason why. Firing up statcast, we see that the average exit velocity – how hard the average ball was hit – on a four-seam fastball in 2016 was 90.5 MPH. For sinkers, it’s exactly the same, 90.5 MPH. For cutters, the average exit velocity was just 87.5 MPH. This difference of ~ 3.333% doesn’t sound like much, but it is. If we look at the average slg% on contact for balls hit at at least 90 MPH, we see a Godzilla-like SLGCON% of .874. But for balls hit below 88 MPH, it plummets down to just .255. That’s…that’s a big difference.
There are caveats galore here. That SLGCON analysis is focused on balls in play, and thus misses the big advantage of the high transverse spin FB: all of the whiffs. It’s also using MLBAM’s definition of cutter, so it might be pulling in more slider-y pitches, perhaps thrown in slider counts like 0-2, 1-2, when SLGCON plummets for everyone, no matter what pitch is thrown. And then there’s the obvious point that averages don’t really help individual pitchers. Jarred Cosart throws a Richardsian 94-95mph cutter 70% of the time, and he got destroyed last year. Stephen Fife couldn’t hack it either. Throwing a weird FB is not a panacea.
It might, however, be a strategic move. Back in 2014, when he was still in the Mets org, Whalen pitched in the Arizona Fall League. Maybe due to pitching at the end of a long season, or maybe due to small sample weirdness, he got hit pretty hard in the desert. Looking at his meager pitch FX numbers from back in 2014, though, Whalen looks completely different. His four-seam was more of a traditional, rising, back-spinning offering. He didn’t yet have a slider, just a slurvy breaking ball that showed *less* spin than average. Everything about Whalen’s movement was just…average (or worse). What he’s done since then is split the meh slurve into an actual slider and a high-spin curve that comes in slower. Gone is the completely normal (but slow) four-seamer, replaced by his cuttery thing. Whalen dominated in the minors despite good-not-great K rates and K-BB% with his new approach. It carried over into the bigs, but was undone by a bout of wildness. This was always Fife’s downfall, and it’s destroyed Cosart, too – Cosart’s career K-BB% is around 3%. Whalen still needs to limit his walks, but the great thing about the cutter-FB hybrid thing is that he doesn’t NEED to post big K rates. Even getting hit fairly hard, and with a HR/9 mark of nearly 1.5 last year, Whalen’s average exit velocity was just 88 MPH, well below average. On grounders, it was under 84 MPH, which is great; too bad he was more of a FB pitcher, but still, it’s encouraging. You can begin to see how Whalen can succeed despite his underpowered arm, and despite the cautionary tales of Fife and Cosart. He may not need Richards’ velocity (Collin McHugh is a 90-91 MPH example), and he may not need a lot of Ks. If he can use his gyro-spinning FB to limit contact authority, he may be better than I initially gave him credit for.