MLB investigation confirms that baseballs have changed

You know the baseballs are different. We know the baseballs are different. Pitchers have been saying the baseballs are different. And now Major League Baseball has acknowledged that the baseballs are different in a report of findings by a team of scientists from some of the top universities in the world, like Stanford, Caltech, and M.I.T.

You can read the whole thing here in PDF form. Here’s the gist ...

The ball is not bouncier -- or “juiced” -- but it is most definitely carrying farther. From MLB.com’s Anthony Castrovince ...

Though the study did not discover meaningful changes in the ball’s lift, it found that the drag coefficient of MLB balls has decreased since 2015. The researchers used a physics model to calculate that if the change in home run rate was attributable entirely to changes in drag, one would expect the drag coefficient to have decreased by approximately 0.012. The exact change in drag coefficient in the time period studied -- if you’re scoring at home -- was 0.0153.

It’s not the seams or the core that has changed -- those aspects were tested -- and it’s not the weather either. In fact, the commision couldn’t figure out what is causing the decrease in drag, despite numerous tests on all elements of the ball. It might simply come down to manufacturing advancements. Looking at you, Rawlings ...

“Rawlings is always trying to improve the manufacturing process to make it more uniform,” Alan Nathan, professor emeritus of physics at the University of Illinois at Urbana-Champaign told MLB.com. “So the interesting question that comes up is whether the goal should be to improve the manufacturing process or to keep the ball performing exactly the way it is, regardless of whether it’s improved or not.”

Baseball Prospectus began studying this three years ago, as home runs began to increase around the league. Their write-up on MLB’s report is a must-read.