New York-de bats from the New York Yankees were the story of the Franchise record nine-home run day of the team against the Milwaukee Bewers on Saturday. Then came the discussion about the actual bats used by some players in the 20-9 victory.
The unique formed wood is the result of two years of research and experiments with a former Massachusetts Institute of Technology Physicist-Coach at the helm.
The question in the middle?
“Where do you try to hit the ball?” Aaron Leanhardt said on Sunday morning in a telephone interview. “Where do you try to make contact?”
Leanhardt, 48, started his work when he was a member of the Minor League of the Yankees department in 2022 and brought it to the big competitions last season when he was the team’s chief analyst, with some players, including Shortstop Anthony Volpe, who she tried in games. Now, according to Outfielder Cody Bellinger, no fewer than five Yankees will use them in games in games.
The bats-with their torpedo-like form-to-measure for player preferences and are designed in such a way that the closest part of the bat is where that specific Slagman usually makes contact with baseball, said Leanhardt, who became a field coordinator with the Miami Marlins in low season.
“Really,” he said. “The point is to make the bat as heavy and as cool as possible in the area where you try to damage the baseball.”
Anthony Volpe (with a “torpedo” bat) congratulates Jazz Chisholm during the 20-9 victory of the Yankees on Saturday. (Mike Stobe / Getty images)
A spokesperson for the Major League Baseball told Athletics That the bats do not violate rules. MLB rule 3.02 states that a bat “will be a smooth, round stick, no more than 2.61 inches in diameter in the thickest part and no more than 42 inches long. The bat must be a piece of solid wood.” It also says that “experimental” bats cannot be used “until the manufacturer has received approval from Major League baseball from his design and production methods.”
Asked if he was the inventor of the technology, Leanhardt said it was a group effort, the results from conversations with coaches, players, MLB and Bat -Makers.
“Credit goes to those who take it,” said Leanhardt. “But if people want to attribute credit to different people, I will take something cut from it.”
However, a Yankees officer said that Leanhardt deserves “a lot” from the credit. Retired Infielder Kevin Smith, who spent parts of four seasons in the Majors, has also credited Leanhardt as the inventor.
Yes, the Yankees have a literal brilliant MIT physicist, Lenny (who is the man), on payroll. He invented the “torpedo”. It brings more wood – and mass – to where you usually make contact as a batter. The idea is to increase the number of “barrels” and to reduce mistakes. pic.twitter.com/CSC1WKAM9G
– Kevin Smith (@KJS_4) March 29, 2025
Leanhardt took an unorthodox route to baseball.
He has a bachelor’s degree in electrical engineering at the University of Michigan and a Ph.D. In physics from MIT. He was a professor of physics at the University of Michigan from 2007 to 2014.
Leanhardt started coaching in the Atlantic League in 2017 and coached at a Montana Community College before he came to the Yankees in 2018. In the Majors in 2024, the club said that he was the first “Major League analysts” and “responsible for integrating the use of quantitative information with on-field performance and preparation.”
Why leave the academic world for baseball?
“I think that is one of the cool things about sport is very competitive,” he said. “Boys are willing to shift the envelope. It’s just a chance to take my background to an area and find ways to innovate.”
Talking to players over the years, it turned out that their biggest worries were two, said Leanhardt. They wanted to make more contact with pitches and they wanted to hit the ball more often with the “Sweet Spot” of the bat, or the closest area.
“They will point to a location on the bat that is probably six or seven centimeters away from the tip of the bat,” he said. “That is where the Sweet Spot is typical. It is just because of the conversations where you think to yourself, why don’t we exchange how much wood we put the tip versus how much we put on the Sweet? That is the original concept there. Just try to take all that excess weight and try to do it where you try to take the ball and then try to take the thinner diameter.
Leanhardt said he did not see many disadvantages to redistribute the weight of the bat.
“The bat speed should remain the same,” he said. “Maybe the bat speed can even increase a bit, depending on how you want to re -design the bat. But in the end you get a thicker barrel, a heavier barrel on the sweet spot. So in a sense you can have your cake and eat it here. You can also get some profit here without actually making sacrifices.”
Leanhardt said he didn’t want to talk about the experiences of individual players with the new bat. Yankees indicated Hitter Giancarlo Stanton told Repectors earlier this month that it was “probably a few bat adjustments last season” that caused the ligament tears in both elbows that led to his current stay on the injured list, although he did not blame anyone. Then he added: “I don’t know why it happened.” Leanhardt refused to comment on Stanton’s situation.
“You should ask the medical staff of the Yankees about that,” he said. “I will postpone all those questions to the medical boys of the Yankees.”
Leanhardt said it was “the nature of our company” that it took years before a radical new bat design would come along.
“In the past, people waved very heavy bats made from Hickory and then someone had this brilliant idea of swinging something lighter, something like Ash, and that was revolutionary in the 1920s, 1930s, ’40s, sort of that transition, and then the industry remained a bit the course,” he said. “Ultimately, people are just needed who ask the right questions and are willing to think ahead.”
He got a kick from seeing the social media Fervor that caused the bats on Saturday. He said that although some players started using them last season, “the entire industry caught some kind of wind” and “it exploded in low season.”
“That’s why you see it in the hands of so many boys,” he said. “It is clear that the implementation of (Saturday) paid a lot of attention for it.”
It took a lot of coordination for the bats to go from the design phase to manufactured. Leanhardt said that he would ‘guarantee’ that he is on a first name base with officials from MLB who supervise the bat regulation and “everyone who operates the lathe for every BAT manufacturer in baseball.”
“You really just communicate with every company and try to find the person who really knows the wood and know how to turn the wood on a lathe. You simply build a relationship with those guys and convince them that this is something that is in their best interest to produce for their players. They want their players to be as successful as possible. Some guys in and it has traction, he said. “That is really how it is structured.”
(Top photo of Aaron Leanhardt, right, with Marlin’s manager Clayton McCullough: Jasen Vinlove / Miami Marlins / Getty Images)