Kagan: The physics of identical homers

From SABR member David Kagan at The Hardball Times on September 5, 2019:

It might seem reasonable to assume two balls hit at the same exit velocity and launch angle should travel the same distance. For example, on April 12 of this year in the eighth inning in Miami, Andrew McCutchen torched this 3-2 pitch for a round-tripper.

Meanwhile, in Los Angeles, Yasmani Grandal sent a 1-0 change-up into the Pavilion in the fifth.

According to Statcast, both balls left the bat at 101.3 mph with a launch angle of 29 degrees. Both dingers traveled 401 feet before returning to Earth. These could be called “identical homers.” Let’s define balls hit with identical exit velocities and launch angles to be “identical launches.” All identical homers are also identical launches, but not all identical launches become identical homers.

With this in mind, let’s examine the homers recorded by Statcast in 2019 through the All-Star break. There were 3,691 of them. That means there were nearly seven million possible pairs of home runs. Of that seven million, there were only about 3,300 identical launches and just 43 identical homers. The McCutchen/Grandal pair were the only pair of identical homers hit on the same day–that’s why I picked them as an example. Identical homers are a very rare coincidence; on the same day, even more so. The rarity of identical homers can be understood by examining the physics of the flight of the ball.

Read the full article here: https://tht.fangraphs.com/the-physics-of-identical-homers/

Originally published: September 6, 2019. Last Updated: September 6, 2019.