It’s no secret J.A. Happ hasn’t exactly been the pitcher the Yankees envisioned when they inked him to a three-year deal over the offseason, and home runs have everything to do with that. His 2.24 HR/9 rate is downright ghastly. FanGraphs lists it as third-highest in the league among qualified pitchers.
Happ’s homer rates have climbed higher and higher since 2015, and to see some regression from a 36-year-old pitcher shouldn’t be a surprise to any baseball fan. However, his jump from 1.37 HR/9 last year to 2.24 this year is more than just age-related decline. Juiced baseballs are almost certainly playing a role in Happ’s horrid start.
The phrase “juicing a baseball” refers to a kind of modification to the composition of a ball in order to boost distance, allowing for more home runs. The conversation around whether or not MLB is juicing baseballs isn’t exactly a new one. In 2017, the league had significantly higher home run rates than in years past, and the baseball community was abound with speculation as to why. MLB conducted a study of the balls used that year and found that while the balls were not bouncier, but they were more aerodynamic. The same thing appears to be happening in 2019.
Baseball Prospectus picked up on the re-juicing of baseballs during the first week of the season. Robert Arthur studied drag coefficients (how quickly the ball loses velocity) and found that drag was lower in April 2019 than at any point during the previous season, meaning balls were going further without needing to be hit harder. Essentially, warning track flyouts in 2018 became homers in 2019, which is where Happ and his struggles enter.
There’s data that indicates J.A. Happ is more or less the same pitcher he has been for his entire career. His 2019 SwStr% and Contact% are a tick worse than last year but still better than his career averages. Moreover, his Meatball% is 6.9, which is the same rate he put up in 2016, a season he allowed 1.02 HR/9. It’s not that hitters are swinging at meatballs more than they have in years past either. Hitters swing at Happ’s meatballs 66.7% of the time, a career low in the Statcast era.
Even when hitters do make contact, the batted ball profile against Happ doesn’t look entirely different from last year. His average exit velocity this season is 88.7 MPH, just a small jump from last year’s 88.1 mph. The jump in EV seems slightly less significant when one considers his launch angle dropped from 15.1 degrees to 14.9 this season. Granted, 15.1 and 14.9 degrees are still both in the line drive range of launch angle, but it does mean hitters are keeping the ball closer to the ground than last year.
Happ had a good year last year, but he was still playing with fire a bit. He’s primarily a fastball pitcher, and his fastball possessed neither elite velocity nor spin. These both contributed to what FanGraphs categorizes as an “awful” 13.5% HR/FB rate. There’s also the fact that Happ is 36, and pitchers generally don’t improve when they’re on that side of 35. The warning signs were undoubtedly there, but many of his stats just don’t justify such a massive spike in homers unless the ball changed.
It’s difficult to say whether Happ will stay this bad over the course of the entire season. He’s trying to evolve. For example, he has moved away from using his four seam in favor of his sinker, but as Yankee fans saw Monday, his new pitch usage strategy hasn’t always brought success.
A few weeks ago Joshua Diemert wrote about how Brett Gardner has benefitted from the juiced baseball. He closed his piece by saying, “[Gardner’s] performance shouldn’t be this good, but introducing a variable like the juiced ball might keep that weird performance going longer than we’d expect.” Something similar could be said of J.A. Happ. His performance shouldn’t be this bad, but introducing a variable like the juiced ball might keep this weird home run spike going for longer than one might expect.