From SABR member Meredith Wills at The Athletic on September 19, 2018:
Baseball’s home run surge is redefining the game. Thanks to MLB’s Home Run Committee report, we now know why the home run rate went up, and my previous article showed what had changed. The remaining question is, “How did this change lead to the home run surge?”
Perhaps now we have an answer.
We already knew that it all comes down to the ball. MLB’s committee found that the spike in home runs was caused by a decrease in the ball’s aerodynamic drag. Basically, a hit at a given speed and launch angle travels farther if the baseball was made after 2015. However, they couldn’t find any physical difference to the ball, so there was no way to explain the change.
My earlier study found that difference: The laces on post-2015 baseballs are 9 percent thicker.
Read the full article here (subscription required): https://theathletic.com/533397/2018/09/19/studying-the-baseball-to-find-the-how-of-the-home-run-surge/
Originally published: September 19, 2018. Last Updated: September 19, 2018.