The struggles of Jakob Junis

Jakob Junis has had a rough first half of 2019.

Counted on to be a stalwart at the back of the rotation in support of Brad Keller and Danny Duffy, Junis has struggled. The raw numbers are unkind. His walk rate has jumped from 5.7 percent and 2.19 BB/9 to his current 8.1 percent and 3.26 BB/9. His home run rate, which was on the uptick last year has continued to climb and now sits at 1.63, 10th highest among qualified starters.

The advanced metrics are similarly rough. At FanGraphs his ERA- of 119 (meaning he’s been 19 percent worse than league average) is fourth worst among starters. His fWAR is 0.6, tied for eighth lowest. Baseball Prospectus’s DRA has him at 6.61, also sixth worst for qualified pitchers. Junis is in negative territory for WARP at -0.9. Again, the sixth worst mark.

Pick a metric. Any metric. The consensus points to the fact the Royals are sending the one of the league’s most underperforming starting pitchers to the mound every fifth day.

What’s happened? Why has his development stalled?

Junis is featuring his slider more than ever. That’s potentially a good thing! Statistically speaking, his slider is his best pitch. Last year, opponents hit .179 with a .312 slugging percentage against his slider and it produced a whiff rate of 36 percent. This year his slider is even better. He’s throwing it with about two percent more spin and hitters are scuffling with an anemic .161 batting average to go along with a .248 slugging percentage. The whiff rate has jumped to 39.5 percent.

But here’s the rub. The numbers don’t always tell the whole story. (WHOA!) The slider is his only pitch. Hitters recognize this and are laying off. They’re swinging at his slider just 41 percent of the time, by far the lowest of his offerings. And those numbers cited above in reference to his slider are relevant only when the ball is put in play. According to Brooks Baseball, against Junis, his slider is going into play only around 13 percent of the time. Again, that’s the lowest percentage of all his offerings.

Hitters are happy to let the slider pass and wait for something meatier. Because they know Junis can’t locate it in the zone and he will eventually serve them something they can eat. And eat heartily they will.

Tuesday’s game against the Indians—his second start against Cleveland in less than a week—featured more of the same.

Junis didn’t want to come in with his slider to left-handed batters, choosing to work away with an attempt at a backdoor slider. Instead, the slider never came close to entering the zone. It was an easy pitch for lefties to avoid.

Overall, Junis threw 23 sliders. One was called a strike. That was a borderline pitch on the outside edge against the switch-hitting Jose Ramirez in the third.

Junis delivered just six sliders in the zone. Three were fouled off. Two were put into play—one for a base hit. One was a missed call by the home plate umpire. When he’s failing to fill up the strike zone with the slider like we saw on Tuesday, the Indians were either fouling off the close pitches, or keeping the bats on their shoulders.

Compare the locations of the sliders he threw on Tuesday against the chart of every slider he had thrown this year prior to that start. He missed in a location on Tuesday where he rarely misses.

Perhaps sensing the need to not lean so heavily on the pitch, Junis moved away a bit from his slider in both his starts against Cleveland.

It’s a trend worth watching going forward, but it’s difficult to say he’s discovered a new way to mix his pitches to keep the hitters off balance. Even with the struggles, manager Ned Yost was encouraged with Junis’s change. “The good thing was his change-up was as good as it’s been all year tonight. We’ve been working on it. It was really, really good.”

For his part, Junis agreed. “Yeah, I threw some good ones. We mixed it in pretty well. I never really got hurt on it... Stole some strikes with it. They fouled a lot off. I’m still looking for that one that can be weakly put into play.”

Overall, Junis offered eight change-ups, five were fouled off. None were put into play. At this point, as Junis acknowledges, it’s still very much a work in progress. The damage was done on Tuesday against the fastball and the sinker. That continues a trend we’ve seen for this entire season.

Solving this isn’t going to be easy. A development of change-up would be nice, but I’m not sure it’s going to help all that much. Besides, when it’s thrown as eight percent of Junis’s arsenal and is still a work in progress it’s difficult to see how it’s going to improve as a pitch.

Junis has taken a step back, but it would seem that this is in large part to a slider that doesn’t challenge left-handed batters coupled with a fastball and sinker that tends to stay elevated. The walks and lack of command are a problem, as is his lack of a putaway pitch. It’s pretty much evolved into a starting pitcher’s worst case scenario. The advanced metrics bear this out.

With the Royals positioning themselves for another high draft selection, Junis has the luxury of trying to work through some issues in a lower pressure environment. However he will need to show some progress over the season’s second half if the Royals are to count on him contributing quality innings going forward.