Jakob Junis is going to get better

Jakob Junis isn’t off to the best start this season if you’re going to focus in on his ERA of 6.14, which puts him at 12th worst of all starting pitchers in baseball. His strand rate of 63.8% is 18th worst of all qualified starters, his hard-hit rate is 36.8% (43rd), and his WHIP of 1.55 places him 12th overall.

The most glaring problem I’m seeing with Junis are his fastballs. They are getting hit to the tune of .308 against his four-seam and .370 (as well as all home runs allowed) against the sinker.

Its hard to say what is going on with them this early, but one factor could be that Junis isn’t getting as much vertical break on either pitch. We are talking a deviation of two or more inches and that can make a significant difference in the type of contact you allow. An inch or two might not seem like a lot but let’s give it a little context.

A baseball bat, at its widest part, is 2.75 inches. Let’s say a hitter is going to make contact on the sweet spot (barrel) of the bat against one of Junis’ fastballs under his average movement. If you give that additional two-plus inches back, you’re looking at contact that is driven into the ground or simply swung over.

Are his mechanics off? Well, Junis is using the same vertical arm slot on his release but his horizontal points have strayed a few tenths of an inch. That doesn’t appear to make a noticeable impact because his spin axis hasn’t changed all that much. He’s getting an additional 150 RPM on his four-seam while his sinker hasn’t strayed much from his career average spin rate.

So what is really going on?

Despite the early shortcomings of his fastballs, there are signs that point to (positive) regression. If you look deeper into Junis’ current metrics, you’ll see that there might be a level of nitpicking, especially with such a small sample to look at.

Junis isn’t really what some of the ‘standard’ numbers are telling us. Have a look at his four starts in 2019. There is a metric below each pitching line, coined ‘Called Strikes plus Whiffs’ (CSW).

Start #1- White Sox: 5.2 IP, 6 hits, 3 ER, 1 HR, 6-1 K/BB-rate
29.3% CSW
Start #2- Tigers: 6 IP, 6 hits, 3 ER, 8-3 K/BB-rate
31.4% CSW
Start #3- Mariners: 4 IP, 8 hits, 4 ER, 1 HR, 6-1 K/BB-rate
31.9% CSW
Start #4- Indians: 6.1 IP, 8 hits, 5 ER, 1 HR, 4-1 K/BB-rate
24.8% CSW

Let’s look into CSW to begin. It was developed by Pitcher List site creator Nick Pollack along with (and written up by) Alex Fast (head of Pitcher List operations). The metric is very simple to understand- it takes all the called strikes and whiffs a pitcher produces in a game and divides it by total pitches. The complete explanation of its legitimacy is detailed in Fast’s latest article for Pitcher List and it should be understood that CSW doesn’t necessarily relate to a good or bad outing but it can give a pitcher’s performance an added level of context.

How this new metric applies to Junis’ starts can be assessed in the following way. According to the classifications, a CSW above 35% is excellent, somewhere around 28% is average, and anything below 25% is bad.

Junis is currently maintaining a 24.5% K-rate, which is the highest of his career. A sizable portion of Junis’ strikeouts are from the slider, equally distributed between both left-handed and right-handed hitters.

Junis has had 72 pitches taken that were called strikes. Of those, 14 were out of the zone (19% overall), but called strikes due to the fact that Martín Maldonado is currently the fourth-best framer in baseball. He and Cam Gallagher make the Royals the fourth-best framing team in the league. I mention this because that’s something else working in Junis’ favor because the potential exists for him to steal a lot of strikes this season.

His walk rate is slightly elevated at 6.1%, but is command is nonetheless strong. Junis has hit the edges of the strike zone with 42.5% of his pitches. That’s slightly better than the league average of 41.5%. The vast majority of those pitches are hitting the lower half of the zone. Expanding further, 26.9% of Junis’ pitches are in what is called the ‘chase zone’, which are outside locations not quite considered waste or bad pitches. Again, we see that Junis is keeping almost all of those pitches low. Junis is currently in the top-25 of all starters in baseball for O-Swing% (chase rate).

Something to seriously consider is his BABIP is incredibly inflated at .385. Of all qualified starting pitchers, that’s the 6th-highest so far this season. Junis has floated around .300 his first two seasons (league average is .297).

Now, I need to point out that BABIP takes about 2000 balls in play before it can be considered stabilized. Currently, Junis has 885 since 2017. So, can’t say with 100% certainty that Junis is due for regression but we can reasonably expect this number to go down. Since 2010, only two pitchers have posted BABIPs above .350- Clayton Richard in 2017 (.351) and and Robbie Ray in 2016 (.352).

BABIP results can have a lot to do with defense, or lack thereof. Almost half of Junis’ contact, 47.1% to be exact, has been groundballs. His GB/FB ratio has been pretty close during his career (1.11) but this season its fluctuated to 1.45. In this case, if the infield isn’t efficient enough to cover a large range, more ground balls are going to sneak through at the expense of the pitcher. As it stands, the Royals overall defense, as we’ll quantify with UZR/150, is 0.5 (zero is average) and that puts them at 16th overall.

OK, so we know what type of contact he’s yielding, lets see where most of it is actually going.

There is a large concentration of contact to the (general) shortstop area. We know Adalberto Mondesi is a good fielder (2.0 UZR/150, 0 errors) and that a decent of Junis’ contact is going into gaps in the defense. Regardless of how good your defense is, its really hard to cover contact that puts the ball where it does in the above chart. With all that said, it is not out of the question to suggest that Junis has just been flat-out unlucky through four starts.

To reinforce that notion, Junis’s ERA of 6.14 is well over two runs higher than both his FIP (3.55, 25th overall) and SIERA (3.79, 26th overall). What this means to the unfamiliar is that on the surface Junis is giving up a lot of runs per game but he can’t be entirely held responsible for the results. To compound this information, Junis has the second highest ERA to FIP disparity of all starting pitchers.

FIP measures what a pitcher can control (walks, home runs, strikeouts) and “measures what a player’s ERA would look like over a given period of time if the pitcher were to have experienced league average results on balls in play and league average timing”. I greatly prefer referencing SIERA as a forecaster because of its high correlation to projecting future ERA.

These bad starts that shouldn’t continue, or at best, be the norm for Junis in 2019. He’s done a good job mixing his pitches this season, even if there is a clear inclination to go with the slider when he’s ahead (mostly to righties). I’d still like to see Junis work on his changeup and build some confidence with it. I also think its worth considering using either the four-seam or sinker full time should he being to incorporate his changeup more.