When Soft and Hard Contact Can’t Explain Home Run Power

Wilmer Difo seems to be taking the Daniel Murphy trade in stride.

He received starts at second base in the first two games of the post-Murphy era in D.C., and he went 3 for 8 with each hit being for extra bases. (He also started for a third straight day on Thursday, though as of this writing, he is taking an 0-fer.) Difo has speed and can spray line drives, but power has not shown up as a key part of his skill set over his time in the majors. The flyball revolution is not for everyone, and Davey Martinez made sure to remind his 26-year-old infielder of that.

Martinez said he told Difo after homering last night to remember that’s not really who he is. So Difo just doubled off the wall in his first AB tonight.

— Mark Zuckerman (@MarkZuckerman) August 22, 2018

Launching flies is great if you have enough power to drive the ball out of the park, but less than optimal if you don’t hit with much authority. Among hitters with at least 300 plate appearances this season, no one has made soft contact at a higher rate than Difo’s 28.3 percent. His 21.5 percent hard contact rate is the third-lowest, trailing only Dee Gordon and Billy Hamilton. Now that it appears that Difo is an everyday player, it’s fair to say that he has the least power of any current regular.

As Difo has improbably racked up extra-base hits against the Phillies, over in the other dugout are a couple of hitters who aren’t too different from him in their batted ball profile. Both Maikel Franco and Odubel Herrera (who homered on Wednesday and Thursday, respectively), have soft contact rates above 25 percent and hard contact rates below 30 percent. Franco’s hard contact rate of 28.6 percent is quite a bit better than Difo’s, but it’s nearly as far away from this season’s major league average of 35.5 percent.

Yet if Herrera and Franco took Davey Martinez’s advice and lofted the ball less often, neither would be flirting with a 25-homer season. They, along with Jonathan Schoop, are the only qualified hitters with soft contact rates above 20 percent and hard contact rates below 30 percent who also happen to have home run-to-flyball ratios (HR/FB) above 10 percent. Though Schoop has gone cold since his trade to the Brewers, he, too, could have 25-plus homers if he finishes with a flourish.

Note: Data in the table below do not include results from Thursday’s games.

While Difo is the outlier in this group, he is much more in line with the norm if we look at all qualified hitters going back to 2014. The graph below plots each of these hitters according to soft and hard contact rates. Not surprisingly, there is a relationship between soft and hard contact rates, but that’s not the focus here. The marks for each player have been color-coded to reflect their HR/FB, and the redder the mark, the higher the ratio. Hard contact rates in particular have been closely tied to HR/FB, as there have been few hitters over the past five seasons who have had a high HR/FB with a below-average hard contact rate.

Herrera’s mark from this season isn’t red, but it’s a pretty pale blue, which is remarkable, given that the only hitter since 2014 who has posted a higher soft contact rate than him was Billy Burns in 2015. Franco and Schoop’s dots are pale as well, reflecting their relatively high HR/FB ratios for hitters with high soft contact rates.

So are Herrera, Franco and Schoop just exceptions that prove the rule? Or are they part of a subset of soft-contact hitters who actually benefit from avoiding the Gordon/Jean Segura route of sticking to ground balls?

One explanation that occurred to me was that perhaps the bulk of this trio’s soft contact was reserved for ground balls, but when they hit the ball in the air, they’re squaring up like they just don’t care. That reasoning doesn’t really hold up, especially for Herrera and Schoop, whose soft and hard contact rates on flyballs are far worse than the major league averages. Franco is making hard contact on flies at an above-average rate, but he is still outside the top third of hitters with at least 100 flyballs.

Having a strong tendency to pull flyballs may play some role  in these hitters’ HR/FB ratios, as Franco and Schoop rank eighth and ninth, respectively, out of 137 batters with at least 100 flies in flyball pull rate. However, Herrera is left out by this explanation, as he ranks 66th.

Maybe we just have to accept that they have been lucky. According to xHR (from xStats.org), Schoop should have five fewer homers this season, while Franco should have six fewer and Herrera should have seven fewer.

But before we close the book on this analysis and declare all three hitters as flukes, there is one stat that makes me think that Franco might be different from the other two. Recall that he is more prone to hit hard flyballs than either Herrera or Schoop, but the difference in their batted ball profiles on flies may be even more pronounced than a mere comparison of hard contact rates would indicate. A notable portion of Franco’s flies have gone a long, long way. He has hit 15 flyballs at least 390 feet — a total topped by just 38 hitters this season. If that does not sound like many hit balls, keep in mind that only 16 hitters have clubbed at least 20 flies for that distance. Franco has just one fewer flyball in that distance category than Giancarlo Stanton, Alex Bregman or Ozzie Albies and only two fewer than Rhys Hoskins and Max Muncy. Meanwhile, Herrera has only nine flyballs hit for at least 390 feet and Schoop has just six.

In other words, all hard-hit flies aren’t equal. In general, soft and hard contact rates are nearly flawless indicators of whether a batter can reliably hit with home run power. Difo probably is better off sticking to line drives and grounders, and Herrera and Schoop may be, too. While fantasy owners aren’t looking to Difo for power, they probably shouldn’t look to either of the latter two hitters either. Franco, however, is having the best full season of his career, posting a higher Iso, HR/FB and Avg than in 2016 and 2017, and it just might be a sign of things to come.