Jakob Junis is off to a nice start despite his ERA

I wrote an article recently where I made the argument that numbers don’t always tell the entire story. This article is based on a similar principle, only this time we’re going to use more numbers to get a better picture of what’s happening, instead of backing away from them.

Jakob Junis’ ERA after three starts in 2019 is 5.74. Among 98 pitchers with at least 10 IP in 2019, Junis’ ERA is the 17th worst. He is up in the zone a little too often, giving up lots of hits, and walking more batters than he did in either 2017 or 2018. Yet, with all of that said, I am more excited about the start Junis is off to in 2019 than I have been for him in a while.

Back in September of 2017, a good friend of mine and former Royals Review contributor Patrick Brennan found an interesting note about Junis from his debut season:

When Junis is on, he’s got some really nasty stuff. You’ve seen him pitch for a while now and don’t need me to tell you that, but I was sitting right behind home plate for his start against the Mariners on Tuesday and, my gosh, it’s sick. When he’s on, it doesn’t take him very long to finish off a batter. If you haven’t taken notice to how good Junis’ stuff can be (particularly his slider), well, take a look:

Junis has taken his game to a new level in 2019. His K% is currently a career high 28.2%, nearly 7% higher than his previous career high. Among the group of 98 pitchers to fire at least 10 innings in 2019, Junis’ 11.49 K/9 ranks 18th. Junis’ whiff rate is up, his strike outs are up, his home run rate is down, his walk rate is up but not significantly, and his ground ball rate is up, so what gives regarding Junis’ career worst 5.74 ERA?

The answer is pretty simple: BABIP. BABIP stands for Batting Average on Balls In Play. It accounts for how often a batted ball (non home runs) falls for a hit. Jake Junis’ BABIP is currently sitting at .409. In 2017 his BABIP was .294 and in 2018 it was .298. In 2017, the league average BABIP was .297 and in 2018 it was .293. So far in 2019, league average BABIP is .287. Junis has had career BABIPs right around league average for his entire career, and simply appears to be getting a bit unlucky so far in 2019.

BABIP can be a fickle statistic to work with. BABIP and luck are not the same. They are generally grouped together, but they are not synonymous. The reason they are often grouped together is because, generally, we can expect BABIPs to regress to the mean over time. Pitchers make adjustments, begin locating the ball better, and their BABIP goes down.

Jake Junis’ hard-hit rate is down from his career norms, meaning opponents aren’t hitting the ball hard as often as they used to. His soft-hit rate is also down from his career norms, meaning opponents are hitting the ball decently just a bit more often than they used to. Fewer balls hit hard helps explain the decline in home runs allowed, but the increase in balls hit decently also explains the rise in Junis’ BABIP.

Only six pitchers that threw 100+ innings in 2018 saw their BABIP stay above .330 for the season. I’m not saying that Junis’ BABIP will definitely dip back down to his career norms in 2019, but there’s a much better chance that his BABIP winds up in the .290s again in 2019 than it does up around .400.

Junis has some things that he needs to clean up, and he certainly has not been perfect in 2019, but he’s been much better than his ERA would suggest. He’s missing more bats than he ever has before, he’s striking more guys out than ever before, he’s allowing fewer home runs than ever before, and generating more ground balls than ever before. He’s going to have to figure out how to generate outs more efficiently, because runs are still scoring, but I’d be willing to be that we’ll see some really nice improvement from Junis sooner rather than later.