Meet the MIT physicist turned Marlins coach behind the ‘torpedo’ bats used by the Yankees

The New York Yankees made history with a franchise-record nine-home run day against the Milwaukee Brewers, sparking a discussion about the innovative bats used by some players in the 20-9 win.

The uniquely shaped bats are the result of two years of research and experimentation led by Aaron Leanhardt, a former Massachusetts Institute of Technology physicist-turned-coach. Leanhardt, who began his work in the Yankees’ minor-league hitting department in 2022, brought the technology to the major leagues last season as the team’s lead analyst. Players like shortstop Anthony Volpe have already tried them in games, with up to five Yankees expected to use them early this season, according to outfielder Cody Bellinger.

The bats, with their torpedo-like shape, are custom-made to player preferences and designed to place the densest part of the bat where the hitter most often makes contact with the baseball. This innovative approach aims to maximize the impact of each swing and increase the number of successful hits.

Major League Baseball has confirmed that the bats comply with league rules, which mandate a maximum diameter of 2.61 inches and a maximum length of 42 inches for bats. Experimental bats like these must receive approval from MLB before being used in games.

While Leanhardt credits a group effort for the bat’s development, retired infielder Kevin Smith and others have recognized him as the key inventor. Leanhardt’s unconventional journey from academia to baseball showcases his unique blend of expertise in physics and coaching, making him a valuable asset to the Yankees and the sport.

The bats’ design aims to address players’ concerns about making more contact with pitches and hitting the ball with the bat’s sweet spot, the densest area. By redistributing the weight of the bat to focus on the sweet spot, players can potentially improve their hitting performance without sacrificing bat speed.

The attention generated by the bats’ success in the Yankees’ record-breaking game has sparked interest across the industry. Leanhardt’s efforts to collaborate with MLB officials and bat manufacturers have been instrumental in bringing this innovative technology to the forefront of baseball equipment.

As the bats continue to gain traction and players experience their benefits firsthand, Leanhardt remains focused on pushing the boundaries of bat design and performance. The impact of his work on the game could revolutionize the way players approach hitting and enhance their overall performance on the field.