Christian Yelich, ground balls, and power

You might have heard of a very fun nugget of information about Miami Marlins left fielder Christian Yelich as of late. It turns Yelich has yet to hit an infield popup throughout his entire Major League career. As Jeff Sullivan of FanGraphs points out in the initial article. this is not a fluke, but rather something that he has been doing since his time in the minors.

This isn’t a skill he’s recently developed. In the minor leagues, Yelich put just about 900 balls in play. He was tagged with eight pop-ups, for a rate a hair below 1%. The average is about 7%. Yelich never hit more than three pop-ups in a year, which helps to explain his minor-league .379 BABIP. And with no pop-ups in the majors, that helps to explain his big-league .371 BABIP.

This is no new skill for Yelich, and it fits right into his reputation as a hitter with a fantastic, clean swing. And Yelich's patience at the plate makes him an ideal leadoff man and someone who knows how to utilize that picture-perfect swing at the right times.

But one reader pointed out something of relative importance for Yelich.

With a 62.8% groundball rate, Yelich trails only Jeter and Revere among qualified hitters. Batting balls into the ground is a decent way to not pop up.

This is one of the concerns about Yelich's game. He has been rolling over on baseballs for much of his career, with a career grounder rate over 60 percent. Only four hitters since 2011 have that kind of rate, and the four averaged a .306 wOBA and a batting line which was just eight percent worse than the league average. Hitting grounders generally is not a recipe for batting success in the majors.

But Yelich is slightly different than those four hitters. All four were of similar archetype; medium-to-low strikeout hitters with good contact numbers and low walk rates. Yelich has the opposite approach, as he took more pitches than all four hitters and both struck out and walked more often in his career. He has only been able to keep up with the three other players in terms of total singles and walks because of his good BABIP on ground balls (.270 career), which may or may not be sustainable.

Even with an abnormal ability to avoid automatic pop-up outs, Yelich's path to improvement is likely to either improve his contact or his power. Perhaps by being more selective, he has already started doing the former. But in terms of the latter, it seems he already has a good amount of it. His results on fly balls thus far in his career have been excellent; Yelich has a .319 BABIP on fly balls, whereas the rest of the league has hit just .084 on those balls this season. Part of the reason for that is the aforementioned complete lack of pop-ups, as those are typically near-100 percent outs. But another reason is that Yelich is already developing some strong pop with his bat. Take a look at a list of the average fly ball distances for each of the Marlins' 10 position players with the most plate appearances (all stats since 2011).

Keep in mind that this excludes any balls in play that are considered "pop-ups," at least by MLB Gameday data. These fly ball distances count only balls that either were flies to the outfield or swings that left the yard. And in those swings, Yelich has the second-best distance on the Marlins, akin to Jeff Baker. If these distances are accurate, then Yelich is already showing off power on the limited fly balls that he has hit.

There are limitations in the data that we have available to us, and it is possible that Yelich is simply hitting a number of balls that are rolling into gaps and are being fielded deep in the field by defenders rather than true drives that have gone 290 feet on average. But the evidence of good distance on his flies and the knowledge that he has a compact, hitch-free swing are good signs for future improvement. The goal going forward will be to find a way to get him to either muscle up more or turn the angle of his level swing into something that can drive harder contact and at least yield more line drives. His role model should be Joey Votto, who similarly does not pop up (0.9 percent infield fly rate since 2011) but has hit line drives in 28 percent of batted balls.

Working against Yelich is his nature since the minors. The 60-plus percent ground ball rate is new to the big leagues, but in the past, his grounder rates have been above 50 percent each year except one. Last season in Double-A, he hit grounders in only 45 percent of balls in play, but that trend reversed itself once he hit the bigs.

It will be interesting to see if Miami encourages a change in his swing to generate more power or if they let him naturally increase his muscle strength and see where it takes him. Rarely do hitters with this kind of an extreme ground ball rate succeed, but the track record of success for Yelich could make him the rare outlier.