Joining the Fly Ball Revolution — May 2019, A Review

In early May, I identified and discussed 17 hitters who had boosted their fly ball rates by at least ten percentage points (30% to 40%, for example) through May 5th. With the fly ball revolution in full swing, these were potentially the newest members. For high HR/FB rate guys, more fly balls is probably a good thing as it will increase homers and runs scored, and probably runs batted in, which should be enough to offset a decline in batting average. Did these hitters maintain their early increased FB% marks or did they experience regression back to 2018 levels over the rest of the way?

As a group, the unweighted FB% increased from 32.3% in 2018 to a whopping 45.7% through May 5 of 2019. While it was a sign for many of the players that a new FB% level was coming, the group did give back much of its gains, but holding onto about five percentage points to push above the league average the rest of the way. Typically, I believe a change in batted ball profile is sticky and signals a real change in approach, but even that being the case, it’s always correct to regress back toward the player’s career average.

One of the driving factors behind Christian Yelich’s career best homer rate, with 44 dingers in fewer than 500 at-bats, was the massive spike in fly ball rate. Since his 2013 debut, Yelich had curiously been an extreme ground ball hitter. His fly ball rates stood in the teens during his first three seasons, then jumped into the low-to-mid 20% range the following three seasons through 2018, before taking this next big step up above 30% for the first time. Now, finally, he could truly take advantage of his over-the-wall power with enough fly balls to make a difference. While he couldn’t sustain that big early FB% over 40%, a mid-30% range was plenty enough an improvement. It’s anyone’s guess whether he’s maintain that 30%+ FB% in 2020.

I didn’t think it made sense for someone with below average power like Jorge Polanco to be hitting so many fly balls, and that over 50% mark early on was insane. He came back down closer to his 2018 mark the rest of the way, but a career high HR/FB rate helped him actually take advantage of all the fly balls. Without those, he would just be hitting a ton of fly outs. Since his steals have dried up, he’s a risky play, as you’re banking on a guy to continue his fly ball ways that probably shouldn’t be hitting such a high rate of flies.

Yup, welcome to the fly ball club, Omar Narváez. The change occurred immediately and he never looked back. Now, he was finally able to take advantage of his league average HR/FB rate. Amazingly, with a huge line drive rate as well, he’s made himself into a very solid hitter and fantasy contributor.

If there’s ever a park to hit as many fly balls as you can, Coors Field is it. For some odd reason, Ian Desmond lost his ability to loft the ball during his first two seasons in Colorado, as he posted FB% marks barely above 20%, easily career lows. This year, he fully rebounded, which led to another 20 homer season despite inconsistent playing time and less than 500 at-bats.

Adam Eaton is now a fly ball guy?! See the Polanco blurb, because it’s the same comment here. For a guy who lives in the single digits in HR/FB rate and has speed, Eaton should not be hitting flies 40% of the time. Amazingly, he stayed at about a 40% FB% all season long, but because of a measly 8.2% HR/FB rate, he only resulted in 15 homers. It’s not a coincidence that his BABIP dipped to its lowest level over a full season. His wOBA also dropped to its lowest mark since 2014, so I’m sure the Nationals would prefer a batted ball profile more closely resembling a speedy, all-fields hitter.

Franmil Reyes enjoyed a thrilling debut in 2018, bashing 16 homers over just 261 at-bats. If you’re nitpicking, though, you would point out the lowly FB% just below 30%. That’s a level you want to see from Polanco or Eaton, not a monster power guy like Reyes. So an early rate of 43% was quite encouraging, but unfortunately, it didn’t last. His FB% did increase marginally from 2018 the rest of the way, but you would still like to see higher than 32%. That fly ball rate gives him both upside and downside cases since we’re not entirely sure where it’s going to land in 2020.

Why on Earth would Dee Gordon think that a 34% fly ball rate was appropriate for his hitting skills?! Smartly, he returned his club membership by the beginning of May, as he posted a more Gordon-like 21.3% FB% the rest of the way.

Is Jose Peraza actually Jorge Polanco? He too should have no business hitting flies over 40% of the time, let alone the 38% he posted in 2018. He’s not a power hitter and never will be one, so he can’t actually take advantage of all those flies with a high HR/FB rate. That’s just more fly balls finding outfielder’s gloves for outs.

Hunter Dozier enjoyed an under the radar breakout, driven by both a jump in FB% and HR/FB rate. That double improvement led to 26 homers a very respectable .360 wOBA. While there’s little chance he maintains a .339 BABIP with that batted ball profile, he has improved his skills enough that he looks fairly decent now, rather than a near lock to lose his job.