If the Ball Isn’t Juiced, Then What Explains the Homer Surge?
Ringer staff writer and FanGraphs podcaster Ben Lindbergh exhibited some excellent reporting earlier this week, obtaining MLB’s study on the properties of its baseballs. It was a valiant attempt to learn whether the ball itself is responsible for the game’s curious home-run surge. Last year, Lindbergh and Rob Arthur went as far as dissecting some balls to study, wondering if juiced balls were the “new steroids.”
This year, the home-run rate on fly balls is 12.8%. Last year, it was the same. Both marks are the highest on record and certainly grab our attention.
Lindbergh has been on the case of the juiced ball for a while. In light of that fact, it’s somewhat unsatisfying that the report he obtained doesn’t support the juiced-ball theory. While this conclusion naturally depends upon the assumption that MLB’s study was conducted in good faith, Dr. Alan Nathan — friend of FanGraphs and professor emeritus of physics at the University of Illinois — was asked by MLB to review the research as an independent source. Lindbergh spoked with Nathan.
“Quite frankly, I was disappointed at that result, because I was hoping I’d find something,” Nathan, who was compensated by MLB for the time he spent studying the BRC report, tells me by phone. However, he says, “I saw nothing in the data that was presented that suggests that the ball has been altered at all.”
Wrote Lindbergh in conclusion:
If the spread of dingers has less to do with COR or seam height than with a wave of Yonder Alonso–like breakouts by hitters who’ve tailored their swings to lift low pitches, then pitchers could exploit those uppercuts by raising their own sights … The historic performance we’ve seen since mid-2015 still supports at least a little skepticism about the true roots of baseball’s home run revolution; without witnessing the tests, we can’t consider these findings definitive. But the “juiced ball” hypothesis does seem much less likely than I thought it did two days ago. “It has every look of being suspicious,” Nathan says about the timing of baseball’s big-fly bailout. “But as I said, there’s nothing I could find that suggests anything amiss.”
Everyone interested in the home-run surge has a theory about its causes.