The Miami Marlins' ground ball kings

The Miami Marlins moved their fences in for the upcoming 2016 season in attempt to goose offense in their preferred direction. However, the Fish are among the worst teams in terms of taking advantage of a shorter fence, in large part because they have three ground ball hitters who own high rates over their careers. Christian Yelich, Dee Gordon, and Adeiny Hechavarria own three of the top 20 highest ground ball rates from 2013 to 2015, with Yelich ranking first with a 62 percent rate and Gordon fourth with a 59 percent rate.

The Fish are depending on three heavy ground ball hitters, each of whom had performances from 2015 that they would like to repeat. For Yelich, that seems almost to be a given, as he owns an almost identical batting line from each of the past two and a half years since his initial promotion in 2013. His .300/.366/.416 batting line by the end of the 2015 year yielded an almost identical .343 wOBA as his career .342 mark. However, he still has an entirely difficult task of propping up a solid batting line almost entirely out of ground balls. Dee Gordon had a fantastic 2015 season, complete with a career-best .333/.359/.418 line (.337 wOBA). Hechvarria kept the gains he made in 2014 and put up a .281/.318/.374 (.298 wOBA) batting line, which is a career-best.

Which of those guys is likely to hold onto these performances, and which ones may be depending on fluky factors? We use some of the data available to us from Pitch F/X to consider some markers.

Pop-Up Rates

As was highlighted recently elsewhere and previously on this site, Yelich has done a fantastic job of avoiding pop-ups over the course of his career. According to BIS data, his infield fly ball rate is the second-lowest in baseball since 2013, behind only Howie Kendrick. But how do the other players fare, and can this be the way they avoid dropping BABIPs?

Yelich not only had good success avoiding pop-ups last year, but he continued the trend he has had since 2013. This goes along with the scouting reports of him having elite bat control skills. Yelich makes solid contact on pitches, has a swing built for line drives, and he pounds so many pitches into the ground that it is unlikely that he will get under balls often enough to pop up.

What about the other two players? Dee Gordon once had issues with pop-ups, having sent 1.7 percent of his total pitches up into the high infield air as late as 2013. But in 2014, that number went down to 0.8 percent of his total pitches, and this past season it was down to just 0.4 percent. It is not nearly the level of Yelich and his 0.04 percent (!) total, but Gordon's avoidance of popups is trending in the right direction,

Hechavarria, however, still has this issue. After dropping his popup rates nearly in half from 2013 to 2014, his numbers regressed back towards a likely mean. Hechavarria has always had a solid-appearing swing, but it is also a long one for a player lacking power. That lengthy swing could be leading to late contact and thus weaker batted balls overall.

Batted Ball Speed

Of course, the data actually allows us to test some of this.

The Marlins' trio of ground ball hitters have varying levels of hard contact made. Of the three, Yelich is the one who makes the best contact, again unsurprising given his scouting reputation for elite bat skills. His ability to bat on ball actually led to a higher than average batted ball velocity, as Yelich's 91.6 mph average beat out the league's overall 88.9 mph mark.

Of the remaining two, one player rated about average and one was near the bottom. Part of Gordon's All-Star transition in 2014 came when he focused on getting the ball on the ground. Naturally, that played better with his skill set but worse in terms of batted ball velocity, as grounders are usually lighter-hit balls than flies. Gordon's ground game led to an average batted ball velocity of just 84 mph, which ranked 216th out of 221 players with at least 190 recorded at-bats for this data set. Meanwhile, Hechavarria put out a near-average season in that regard, as his 87.5 mph mark was 159th.

But these players so often put the ball on the ground that it may be more relevant to visit their ground ball velocities rather than their overall averages.

Yelich had the best average velocity on ground balls as well among the three. His 89.4 mph average was not exactly on par with big-time power hitters like Miguel Cabrera or Lucas Duda, but it was good for 32nd in the league among this data set. Hechavarria's ground ball velocity held up decently with a ranking of 87th in the league. Both of these guys managed grounders that were above the league average ground ball velocity of 86.6 mph.

The laggard was Gordon, whose grounders were among the weaker ones in the league. His 82.9 mph rate was 207th in baseball. Alongside him were a slew of light hitters like Alexi Amarista, Ichiro Suzuki, and Ben Revere. Of course, Kris Bryant was also there, which tells you that this is not a perfect marker for elite bat skills. Then again, power hitters like Bryant have swings more built for fly balls, meaning their grounders are more likely to be mishit. Gordon is trying to hit grounders, but his are still weaker than average.

Infield Hits

This aspect of the game appears to be stable for the three players. Of the three, obviously Gordon takes the most advantage of this. Gordon's speed is his most elite tool, and he is among the fastest players in the game. This is one part of the game where Gordon holds such a distinctive edge that it is a huge benefit to his ability to continue his high BABIP. He owns the eighth highest rate of infield hits per ground ball in the game, alongside other speedsters like Rajai Davis, Mike Trout, and Billy Hamilton. When combined with his ground ball rates, Gordon owns fourth highest number of infield hits per plate appearance at five percent. Yelich and Hechavarria at rates closer to half of Gordon's mark.

Based on these three markers, it seems obvious that Yelich has the greatest chance of repeating his performance. His markers point to a great ability to control his swing in a way elite hitters can, with the ground ball plane of his swing being the only problem separating him from developing into a star hitter. Gordon is on his own extreme in batting profile, with a speed advantage but a deficit in hitting the ball hard enough. However, with the appropriate trending popup rates, he can balance out some of his issues, issues for which Hechavarria has no balancing factor. While Hechavarria has put up close to league average batted ball velocities, his lack of elite speed or avoidance of popups combine with high ground ball rates to make him just another high-grounder hitter. The prospects of him continuing to improve are less than those of Gordon and Yelich maintaining some semblance of their 2015 seasons.