Hit trajectory is the rage today with hitters like Yonder Alonso, Daniel Murphy and Ryan Zimmerman all recently seeming to remake their careers due to focus on hitting the ball in the air rather than on the ground.
While the season is still young, the sabermetricians say that it only takes about 80 balls in play for ground-ball and fly-ball rates to stabilize. We’re about there for hitters unless they have struck out an incredible amount. So let’s look at all these rates now for qualifying hitters, through Sunday, to see which have improved the most vs. last year in this seemingly concerted effort to change the plane of the swing in order to get better loft on the ball when hitting it squarely. And we’ll also see who is losing this battle as pitchers and teams are also aware that ground balls are far less threatening when it comes to altering the scoreboard and are presumably trying harder than ever to induce them.
I pulled only hitters whose rate of ground balls is at least 10 percentage points different year to year. What this means, given that stabilization of a statistic only says that it’s reasonably at least half skill, is that even if we cut the rate in half and attribute the rest to completely random factors, the result is still at least five percentage points of hit trajectory change (meaningful).
So let’s look at Alonso, who has gone from a 44.6% ground-ball rate in 2016 to 26.5% this year. That’s the major reason his homer total of nine matches his career high. But let’s ballpark his rate going forward at half that difference — or 35.6%. That’s still a radical change so the bottom line with Alonso is that it’s likely he will continue to hit far more homers than we projected in March. I would bet on about 16 more for the balance of the season.
Some players have improved their rate of fly balls without boosting their homers. Others have seen dividends. The complete list of hitters at least 10 percentage points better at avoiding grounders this year vs. last year are, in addition to Alonso (the MLB leader): Jed Lowrie (13.6 points better), Zimmerman (12.2), Jay Bruce (12.2 from a previously extreme fly-ball level), Trevor Story (12.0 and also previously extreme), Joe Mauer (11.7), Orlando Arcia (11.4), Josh Reddick (11.4), Francisco Lindor (11.3), Scott Schebler (11.0), Jose Bautista (10.5 and previously extreme), Jose Ramirez (10.5) and Josh Harrison (10.4).
Lowrie has only two homers. But he hit 16 in 340 at bats in 2012, albeit in a better park (Houston). He otherwise has an OPS 27% better than the league average. If the power comes as this stat predicts and Lowrie reverts to career norms of HR/FB of 6.5-to-11%, he should hit 10-to-12 homers for the balance of the season and thus become playable in 12-team formats batting at the top of the A’s lineup.
Reddick has hit 32 homers in the past and is worth rostering in all formats if you believe in this stat. I’m not trying to hedge on that but we don’t have a lot of data on hit trajectory and power in this league-wide context of hitters trying to change it. Reddick also has an OPS 17% better than average through Sunday. And he’s 11% owned. I’ll bet on 20 homers the rest of the season.
Lindor’s power spike seems bettable. Ditto his teammate Ramirez. I’ve liked Schebler since March given how his park plays for lefty power, but the issue for him was hitting too many grounders, like worm-killer Christian Yelich (still up to his old antics). But now that this problem has been seemingly rectified in dramatic fashion, I love Schebler going forward as a legitimate source of 30-homer power.
Harrison is translating his fly balls into homers and it does not seem like a fluke. If you’re too late on Harrison (he’s 45% owned), just get Lowrie (4% owned but profiling the same and with more power historically).
Guys to worry about — meaning they’re doing the opposite of the current trend by hitting more ground balls: Alex Bregman (20 percentage point spike in ground-ball rate), Kevin Kiermaier (16.8), Alex Gordon (15.7), Trevor Plouffe (15.7), Travis Shaw (14.7), Brandon Belt (14.0), Robbie Grossman (13.5), Gregory Polanco (13.2), Freddie Freeman (12.5), Justin Upton (12.0), Xander Bogaerts (11.4), Jose Altuve (10.7), Yasmani Grandal (10.6), Brian McCann (10.6), Victor Martinez (10.5), Asdrubal Cabrera (10.2) and Charlie Blackmon (10.0).
There are some interesting counter examples of hitters smacking homers despite apparently going the wrong way on hit trajectory. So you can look at Freeman and Shaw and feel confident that if their HR/FB normalizes (career high 37.9% for Freeman and 28.0% for Shaw), they can maybe hit more fly balls in line with their historic rates. So I’m not selling either based on this. But the players above who are not hitting homers may struggle to do so all year unless their now stable rate of hitting ground balls proves against the odds to be a radical fluke.