Jakob Junis was expected to take the next step for the Kansas City Royals this season but a closer look at his numbers shows that took a step back.
Jakob Junis was a very nice surprise for the Kansas City Royals’ rotation in 2018. He was coming off a year in which he started sparingly in the first half of the 2017 season but was a regular down the stretch of the second half. Highlighted by a couple of masterful performances that saw him strike out 7 batters in at least 6.1 innings, the arrow was trending upwards for Junis heading into 2018.
As noted, he followed his rookie campaign with a very productive season in which he made 30 starts for the team and was excellent in the second half with a 3.35 ERA in 13 starts. Junis relied heavily on his slider in 2018 and had tremendous success with it, limiting opposing batters to a 0.179 batting average and had 126 of his 164 strikeouts come from this pitch. StatCast indicated that his slider had 3.8 inches more drop – or 9 percent more – than the league average and 7.5 inches of horizontal movement – or 107 percent more – than the league average. Those are incredible statistics and it’s fairly easy to see why he utilized the pitch so often. Heading into the 2019 season, it appeared the Royals had found a gem in the 29th round of the 2011 MLB Draft.
However, things didn’t go as planned for Junis. He decreased the usage of his slider from 34.2 percent to 29.7 percent in 2018 and 2019, respectively, while increasing the usage of his curveball from 6.6 percent to 14.1 percent. The problem here is that Junis allowed opponents to slug 0.559 off his curveball in 2019. Albeit, it was less than 2018 (0.591) but it still didn’t make a whole lot of sense why he would want to use this pitch more often. Especially when he was experiencing so much success with his slider.
Speaking of, opponents hit just 0.152 off Junis’ slider this season and a remarkably low 0.232 slugging percentage. He vastly increased the spin rate on his slider from 2018 when it was at 2474 RPM to 2522 RPM in 2019. It’s just hard for me to understand why he backed off the pitch, especially when he was producing a 38.2 percent whiff rate this year on his slider.
Junis’ fastball usage remained roughly the same from 2018 but opponents were able to slug 0.636 off it this past season and connected for 15 of the 31 home runs he allowed. I would expect that next season, Jakob Junis will get back to what was working for him in 2018. When your fastball has 12 percent less vertical drop and 18 percent less horizontal movement at 92 mph, the location of your pitches has to be your friend along with the proper usage of pitch selection.
He’ll likely be penciled into the rotation for next year but he will need to right the ship quickly. Junis allowed a career-high 41 percent hard-hit rate with an opponents’ average exit velocity of 90.0 mph on batted balls, which puts him in the bottom 9 percent of the league.
His month of September left a lot to be desired, as he was knocked around to the tune of an 8.59 ERA in 3 starts. It’s not exactly encouraging heading into an offseason that already has more questions than answers for both Junis and the Kansas City Royals.