Even though MLB commissioner Rob Manfred insists, time and time again, that the baseball has not changed over the last three years, an ever-increasing pile of evidence continually insists the contrary. The first landmark study came last year in The Ringer, where Ben Lindbergh and longtime sabermetrician Mitchel Lichtman found that, “The newer balls [after the 2015 All-Star break] have higher CORs [coefficient of restitution, or bounciness] and lower circumferences and seam heights, which would be estimated to add an average of 7.1 feet to their distance, equivalent to the effect we would expect to stem from a 1.43 mph difference in exit speed.”
That was mighty convincing, and nevertheless, Rob Arthur and Tim Dix of FiveThirtyEight topped it with visual evidence. They discovered “the outer (pink) layer of the core, which was, on average, about 40 percent less dense in the new group of balls.” The belief is that Rawlings changed their manufacturing procedure to reduce inconsistencies in the ball, and thus, they inadvertently created one with a less dense core.
There are — as of yet — no plans to change manufacturing procedure. don’t think there is any evidence that this was some sleight-of-hand to increase offense from the 2014 malaise. Nonetheless, ignorance to the change means that MLB has no intention of course-corrections. So, the teams benefitting from the new ball will continue to reap the rewards.
This is why players like Yonder Alonso are embracing the so-called fly ball revolution. As Joshua Diemert found, Didi Gregorius and Brett Gardner saw a massive increase in home runs because of the ball, a changed approach, and the short porch. That doesn’t mean the advantages are all positive—Diemert also found that the pitchers are adversely affected—but the batters will make up a significant portion of the team’s value this season.
This matters, obviously, because the Yankees are going to orient their roster around this trend. That’s why they traded for a player like Brandon Drury, who has shown a tendency to hit to the opposite field over the short porch. You could imagine this strategy also being deployed to another new acquisition, Giancarlo Stanton. Taking pitches to right field as a ball bears away from him could yield a few more home runs, which is pretty good considering his median ZiPS projection is 55 home runs.
The Yankees are a power-hitting team, and since the trade for Babe Ruth they have constructed their roster around the idea of hitting home runs to right field. When the Yankees dealt with the supposed “wind tunnel” as the new Yankee Stadium opened, it was an advantage that was short-lived. After the season a panel was installed to thwart the wind, and their 244 home run total in 2009 dropped to 201 in the following year despite the fact that their team wRC+ (112) was identical.
The Yankees are in the very fortunate position where a simple ballpark change won’t eliminate their advantage. Sure, every team has access to the data that unleashed the fly ball revolution, and I would imagine front office people are aware of this juiced ball research. As I mentioned, pitchers would also be affected. Masahiro Tanaka, for example, will need to find his way in this new era. When a team is uniquely powerful, though — when Stanton, Aaron Judge, and Gary Sanchez hit in the middle of your lineup — the juiced ball has a multiplicative, positive effect. The research is very clear: the ball is different. Luckily for the Yankees, they are primed with what could be the most powerful lineup of the decade.