MLB home run surge: Altered baseballs or altered mindsets

Aaron Judge’s blasts during the Home Run Derby remind us once again that altered baseballs could possibly be responsible for the surge in home runs.

There’s nothing new about the idea that altered baseballs are responsible in the surge in home runs across Major League Baseball. If the current trend continues, 2017 will see a new single season record in home runs with a huge margin over the previous record, but could altered baseballs be the cause?

The 2017 Home Run Derby saw several baseballs that would have flown out into the parking lot if not for the windows at Marlins Park. Aaron Judge, the Derby champion, sent four balls a whopping 500 feet or more during his lights-out performance.

Judge is known to be one of baseball’s powerhouses, a true slugger whose swings pack an enormous amount of power. Interestingly enough, Judge’s powerful swing is one of the counterarguments to the whole idea of altered baseballs: the increase in home runs is due to stronger players and changes in pitching, not altered baseballs.

Ben Lindbergh of The Ringer, co-authoring with Mitchel Lichtman, posits that “juiced” baseballs are responsible for the increase in home runs. “Juiced,” in this case, refers to balls that have been manipulated, mainly in their design, to be bouncier. The extra bounce helps those balls go further when hit. The research conducted to support this claim dates back to just after the 2015 All-Star Game:

"“The current barrage began in earnest immediately after the 2015 All-Star break, leading to the largest increase in the rate of home runs/batted ball between a season’s first half and second half since at least 1950 (when Baseball Prospectus’s database begins). That increase coincided with a significant rise in the average exit velocity of batted balls, which largely explained the extra home runs but effectively replaced one mystery with another, leaving us wondering instead why balls were leaving bats with such speed. (Giant baseball-obliterator Aaron Judge didn’t debut until late [2016] so we can’t blame him.)”"

This is where the studies trying to pinpoint the cause of the increase in home runs began in earnest, by examining games before and after the 2015 All-Star break. Theories (and conspiracy theories) abound, from weather to better conditioned hitters, the strike zone, and managers being more savvy about their batting order and when to pull starting pitchers.

There is a lot of research that went into these studies and I’m not going to even try to regurgitate it here. (You can read it all here) It’s a lot of math and physics tied into the study of baseballs from different games at different points in the season. Mitchel Lichtman, a former MLB consultant, conducted an independent study upon which he and Lindbergh based their article. Some of the things they focused on were seam height, circumference, weight, dynamic stiffness, and COR (coefficient of restitution) or bounciness. All of these factors, in varying combinations, can contribute to the balls carrying farther when hit.

While the balls that were tested for this study don’t fall outside MLB regulations, the Baseball Research Center admitted back in 2000 that “two baseballs could meet MLB specifications for construction but one ball could be theoretically hit 49.1 feet further.” This means that these minute differences in ball construction can fly under the MLB radar but have very different responses when hit in a game. This is where the focus needs to be in future studies.

Major League Baseball is staying mum on the issue, satisfied that their own testing dismisses the notion of juiced balls. However, the numbers are difficult to ignore and future studies should be conducted, introducing all of the variables such as increased temperature, lineups, and guys who train to swing away. If this trend continues, then 2018 could see the projected 2017 record fall.

Next: MLB 2017: One X-factor for each team

The Aaron Judges of the world are the flukes with their five 500-foot homers. While there will always be guys with that kind of power, they are the exception, not the rule. That’s why we absolutely should be asking why this surge in home runs has been happening, and why it started so abruptly in 2015. We live in the Statcast era, after all, and there are too many moving parts for it to be a coincidence or fluke. Are we working with altered baseballs, or is something else going on?