Photo Credit: Bill Kostroun/New York Post
In the space of about three years, baseball has seen a reversal of fortunate for the batters. Hitters are hitting home runs at historic rates — the single month home run record fell in June — and there has been a rush to figure out why the home run rate has surged; the primary focus has been on changes to the ball itself (aka “juiced baseballs“).
Veterans began to openly discuss the changes they thought had been made to the baseball. They had noticed that the seams seemed lower and that the ball was harder than it had been previously.
The findings in the data have anecdotally been supported by several players and coaches. New York Mets manager Terry Collins said in an interview with the Orange County Register, “The seams on the ball are definitely lower. … And there’s no question that the ball is harder.” Collins joined a chorus of established veterans who claim that the ball has changed this year, including Justin Verlander, Andrew McCutchen and Jake Arrieta.” – Rob Arthur, FiveThirtyEight
This evidence of anecdotal changes to the ball seems to be confirmed by a chart that was created by Arthur in his piece on FiveThirtyEight. Using Statcast, he measured the air resistance of baseballs and compared them against the numbers of dingers that are being hit. There’s a strong correlation between the lack of air resistance on the baseball and the number of dingers that have been hit.
This increase in home runs has led to some incredible performances, individual and collective, in 2017. Fans have already seen a seven grand slam day, the record for number of home runs in a month fall, and rookie Aaron Judge smash more home runs than any other rookie in Yankee’s history.
The surge in dingers started after the 2015 All Star Game, and the home run rate has only continued to increase since. In fact, we’ve seen more home runs in the the last two seasons than we did any any two seasons of the steroid era combined.
If the juiced ball hypothesis is correct, the crazy thing is that these changes to the balls doesn’t violate MLB rules.
As an earlier ball-testing report by the Baseball Research Center that was publicly released in 2000 acknowledged, “two baseballs could meet MLB specifications for construction but one ball could be theoretically hit 49.1 feet further.” – Ben Lindbergh, The Ringer
The changes to the seams of the ball can be small, still within the regulated variance, and will increase the distance that the ball will fly, which will increase the distance that the ball will fly. And the crazy thing is it wouldn’t take a very large variance in the seam heights to completely change how far the baseballs fly, only 0.12 COR can dramatically increase the distance the ball will travel — which is well within the variance of 0.514 to 0.578.
The bottom line is this, MLB seems to have made a change to the balls that are well within its rules and it’s led to an increase in dingers; and as everyone knows, chicks dig the long ball*.
*Yes I know, everyone digs the longball. I just wanted an excuse to put this awkward commercial in this post.