There’s a growing consensus that the 2017 MLB season featured a ball that behaved differently. The Ringer had the best breakdown of the belief in an overly-tightened baseball, resulting in a higher Coefficient of Restitution. In layman’s terms, the ball bounces more on contact with the bat. This led to the year of the home run, which saw more long balls in 2017 than any other season in baseball history.
Rob Manfred’s office has denied any change, but both published research and anecdotal evidence from players point to a different baseball, yielding questions about what ball will be used in 2018. Whether MLB goes back to the “old” ball, keeps the juiced version, or opts something in between, it’ll have an effect on the Yankees’ lineup.
A juiced ball doesn’t affect all players equally. Hitters like Aaron Judge, Giancarlo Stanton and Gary Sanchez have the power to clear the 40 home run benchmark with ease. The lesser hitters in the lineup, however, appear to have benefited greatly from an augmented ball.
Towards the end of the season, Andrew Perpetua at FanGraphs detailed the added distance from a new baseball. Essentially, the ball gives players an extra five feet or so, which doesn’t sound like much until you think of all the warning track fly balls that now become home runs. By comparing the added effect of the juiced ball with a player’s expected home run total, based on launch angle and exit velocity, one notices that two Yankees benefited the most.
Now, both Gregorius and Gardner are left-handed hitters at Yankee Stadium, meaning their numbers are probably going to be artificially inflated anyway. Those 22 combined home runs that, in theory, shouldn’t have happened still represent a huge chunk of potential runs for next year’s squad. Overall, hitters would have lost about 20% of their total home runs if the league had used the older ball.
There’s also the effect the juiced ball had on various pitch types. The Yankees were spectacular hitting the fastball in 2017, while also being above the league median against sliders and curves. Many pitchers, however, have complained that the new ball made it harder to throw breaking pitches, possibly artificially lowering their effectiveness league-wide. Should MLB revert to the older ball, pitchers may find their breaking balls more effective, further hurting a strength of the Yankees.
There’s no word on whether the ball will be different in 2018 or not. Nobody should interpret this as a sign that a change will or won’t come, though. Baseball gave no alert that the ball would change midway through 2016, and continues to deny any juicing in the face of both published and anecdotal evidence. Still, the ball is probably different, and whether it’ll stay the same in 2018 or not will factor into what we can expect from the non-Judges of the world.