Fixing the changeup will be key for Jakob Junis

Jakob Junis was impressive in his first spring training start against the Arizona Diamondbacks. Through three innings, Junis gave up three hits, a walk and four strikeouts while allowing one run. His pitches were well sequenced and showed some nice movement. What I felt he did best was impede hitter timing as evidenced by his velocity chart below.

Here’s a visual example of how Junis worked hitters. This is a three-pitch strikeout of Jake Lamb which saw his pitch sequence go 92 MPH four-seam, to 84 MPH changeup, to 93 MPH sinker.

The quality of hitters Junis faced (OppQual), according to Baseball Reference, was rated a 7.8 out of 10. BR’s rating system is scaled to hitter skill level, with a 10 being an MLB-type batter, an 8 being AAA, a 7 would be AA, and so on. Junis’ rating is near the high point of OppQuall most pitchers face during the preseason.

Junis mainly utilized his fastball and slider with his changeup and sinker showing up sporadically. Three of the four (FB/SI/SL) strikeout pitches are shown below.

The four-seam fastball, sinker, and slider were his main pitches in 2018. He threw a curveball which fell out of favor very quickly and was gone by July. That allowed for an uptick in his changeup, a pitch that did not work out well for him last season yet is necessary for Junis to become a next-level pitcher. That sounds simple enough except Pitch Info’s Pitch Values rated it the 8th worst in 2018 (-2.22 wCH/C). It was thrown 166 times last year producing just two strikeouts with hitters posting a .342 batting average.

With the exception of his slider, he hasn’t shown much swing-and-miss stuff. Overall, his chase rate is 30%, in line with the MLB average, and his zone contact (89%) is a bit worse than the 85% most MLB pitchers yeild.

With other pitches considered, it was the changeup that created the highest rate of whiffs (this article by Alex Duvall is a great overview of the changeup’s potential). That’s good for Junis because he has the propensity to keep hitters off-balance by shifting velocity. That’s a pivotal skill for guys that don’t regularly show electric stuff. Despite his low fastball velocity (~91 MPH), his slider is slow enough (82 MPH) to create good velocity spreads to mess with hitter’s timing.

I want to point out that only looking at whiff rate keeps context out of the picture because we don’t know how he sequenced his pitches prior (FB-CH, SL-CH, SI-CH). I mention this because Perry Husband, the man who pioneers and champions Effective Velocity, indicates that hitters have an ‘attention zone’ where they are geared to a finite speed range. Altering that range can create timing issues which induce those swings that some fans like to emote with “What was he swinging at?!”.

As you saw in the gif earlier, he’s adept at tunneling either pitch in tandem (FF-SI, FF-SL, SI-SL). Not only that, his release points on each pitch are incredibly close. I wrote an article over at Pitcher List detailing the importance of tight release points when tunneling.

Junis seemed to have some issues with hung changeups in 2018. The three clips below shows some examples of the damage caused when this happens.

Given the type of movement Junis creates with the changeup keeping it down is critical, and he does that a good amount but mistakes with the pitch cost him dearly.

The velocity is right around league-average (84.7 MPH) but the spin rate is much lower (1487 RPM) than the rest of baseball (1770 RPM). What this means is his change will drop a lot earlier than usual due to the Magnus Effect. The later (and sharper) you can have your pitch break, the higher the probability of topping the pitch and driving it into the ground. That lowered spin rate causes the changeup to drop early enough to allow hitters to catch on and time the pitch while alter their swing angle’s accordingly.

Junis had difficulty throwing the pitch for strikes (41% went for a ball) so it could stand to reason that when he needed a strike, he aimed higher in the zone which resulted in a lot of tattooed baseballs. But again, I can’t make assumptions without knowing what he intended some of those pitch to be. Obviously every pitch isn’t meant to be a strike.

On Saturday, Junis was doing something a little different with the pitch. There seemed to be an adjustment on the changeup’s spin axis (219 degrees) considering the 2018 spin axis floated around 240 degrees. Junis had also altered his release point by 2-3 tenths of an inch in towards home plate. It also looks as though Junis has improved upon his spin rate since the pitch hung a bit longer than his average changeup.

Here is a swung on changeup from the Lamb at-bat.

The presumed aforementioned alterations, even as slight as a tweak to arm angle, impact the type of movement he can get with the pitch. Perhaps Junis has figured out the key to handling the changeup better, and if this revision sticks, we may notice a scarcity of hard contact while seeing an accretion on chases.

This could also impact his contact tendencies by creating more groundballs, which would be benefical to Junis. His flyball rate wasn’t terribly high (37%) but what creates the desire to see more pitches hit into the ground is his elevated HR/FB rate of 16%.

I want us to come back down to earth a bit because he only threw the changeup six times, but it provides some hope that he might be able to use it more effectively. I can’t find any data to back this up but you can look at some of the better pitchers in baseball and see they have at least four pitches they through with regularity. There are exceptions of three-pitch pitchers but their repertoire tends to be quite exhilaratory.

The Royals are going to need the staff to pitch at a high level. Concerns about scoring runs are abound, though we see some spark from the lineup this spring. We can’t put much stock into that but suffice it to say the Royals will be challenged to keep up in high-scoring games. If the Royals have Junis stepping up, the task could be less daunting.