You’re not crazy: the Royals have been popping up at a prodigious rate

So much fly balls

In the first few weeks of the season, it seemed that every single out the Royals made was an infield popup or a ball that further went up in the air than it went out from home plate. In the weeks since, the Royals have made some other kinds of outs. But it sure seems like the Royals are hitting an unusual number of outs in the air.

I have good news (or bad news, depending on your point of view): the trend is not in your head. The Royals have hit into a lot of popups and fly balls.

That info is not good for the Royals because of how hits work. Whether or not a ball becomes a hit is largely dependent on the launch angle that the ball comes off the bat and its exit velocity. As you can see from this chart from Fangraphs, the ideal launch angle is between 10 and 15 degrees, where the batting average on balls in play (BABIP) and expected weighted on base average (xwOBA) peak at the same time.

This makes sense: balls hit at a 10 to 15 degree launch angle tend to nearly universally go over the head of the infielder and fall before the outfielder can catch it. From there, it gets a little complicated: home runs don’t count as “in play” so they are excluded from the BABIP data set. But xwOBA takes into account all batted ball events, and you can see a spice at around 30 degrees which represents the sweet spot for home runs.

But even when you take into account home runs, production decreases significantly as the launch angle creeps up. Once you get to 40 degrees, xwOBA falls below .150 and BABIP is only at .050. In other words, if you don’t hit the ball hard enough to get it out of the park at that angle, you’re not getting a hit.

Broadly speaking, batted ball events fall into one of three categories: ground balls, line drives, and fly balls. A special bonus subcategory, infield fly balls, is also notable because infield fly balls are near automatic outs.

So let’s start there: how do the Royals as a team rank in infield fly balls?

• 11.9%, 6th highest in MLB

That’s not good. How about fly balls in general?

• 45.8%, highest in MLB

That could be good or bad, depending on how hard the Royals are hitting the ball. Let’s look at hard hit rate and then the percentage of fly balls that result in home runs?

• Hard hit rate: 39.5%, 15th in MLB
• HR/FB: 4%, lowest in MLB.

So, to recap: the Royals are hitting the ball in the air more than any team in baseball. A lot of those balls aren’t leaving the infield. And they hit the ball hard at a mediocre rate. This combines to mean that the one benefit to hitting fly balls—hitting home runs—just isn’t happening.

Is it Kauffman Stadium’s fault? That’s certainly a factor. The Royals have hit the ball hard and in the air some, and Statcast’s expected home run stat says that the Royals should have hit 5.6 more home runs than they have.

But that’s not something to focus on for a pair of reasons. One reason is that even with the additional 5.6 home runs, that brings the Royals from 30th in the league all the way to...29th in the league. The second reason is that, well, who cares if the Royals should have or would have hit more home runs elsewhere; they are hitting half their games at Kauffman Stadium, and their approach should reflect it accordingly.

There are four players who have been particularly bad at the whole popup/fly ball thing so far. Three Royals have a fly ball rate over 50%: Vinnie Pasquantino, MJ Melendez, and Jonathan India. One more player—Kyle Isbel—has an infield fly ball rate at an eye-watering 31.8% (that’s out of his total fly ball rate, which is at 48.9%). MJ got sent down to Omaha because his swing was out of whack. Isbel has seen his playing time go down as other outfielders play center field more often. And India has still managed to get on base at an ok clip despite so many easy fly ball outs.

(Vinnie is a discussion for another day; that’s a big problem right there)

How much of an issue is this? We’ll see. It’s still early, so maybe it’ll fix itself. But the longer the Royals keep hitting balls in the air but not hitting home runs, the coaching and approach comes more and more into focus as an area of improvement.