Thirty-seven square inches isn't a generous amount of string space to hit a tennis ball with. That's exactly the point of the Saber training tool for tennis, a product that has now reached the upper echelons of a sport not known for on-court aids.

Developed by Fabio Molle of Functional Tennis, the Saber offers an evolution on an aid he'd sold since 2018: a wooden spoon. The concept is the same, but the execution has led the Saber into the hands of everyone from Novak Djokovic to Daniil Medvedev and Hubert Hurkacz to Taylor Fritz.

"It prompts players at any level to really focus and take care of contact of any stroke," David O'Hare, Davis Cup Player and ATP coach, tells me. "To me, the Saber is a very versatile training aid. It can have an impact at various levels of the game."

In a sport with plenty of off-court scientific advancements around training, O'Hare says he doesn't know of many training aids as beneficial as the Saber on the court. "There is a space for improvement in on-court tools, in my opinion," he says. "The Saber is a great example of this."

So, the 37-square-inch head tennis racket was born, thanks to a wooden spoon. The main point behind the small head size is to get players to intently focus on their contact point. Not having much surface area to work with does the trick. While a large wooden spoon—Molle sold this tool as the "tennis pointer"—did the trick, it wasn't until Ireland-based Functional Tennis created an actual racket that the aid took off as something others couldn't knock off.

Through design iterations and research and development, Molle had his first prototype in spring 2021. By summer 2022 he was selling the racket and now one year into production, he's seen the growth of the product.

The 37-square-inch head size was not too big to make it easy to use, but not so small that there wasn't some give that enables rallies, Molle says. The prototyping phase also ensured the racket felt as close as possible to a full-size version—including with a 300-gram weight common in the market. A special string for the racket developed in conjunction with Solinco was released this year.

Molle says spending time during design to work with experts in the field helped him shape a product that feels like a racket, but with the unique design that fills a need not served in the industry.

"It's used to help players work on timing, on their contact time, correct ball tosses, remove swinging form volleys and so many more areas," Molle tells me. "Players use it at the start of a session to get focused in on feeling the ball, feel the impact point and just to get focus activated. It then enhances the feel when they switch to their standard racket."

O'Hare says a productive stroke requires the player to maintain an axis of rotation by keeping the head still and rotating around it. "Utilizing the Saber in practice is a fantastic way to encourage this while also making it challenging and fun," says the coach of a major doubles champion. "In developing players it's a fantastic way to start the session. Warming up with the Saber encourages good focus and engagement right away. Every athlete I've worked with has responded really well to working with the Saber."

Having a true racket experience adds a bit of intrigue. Molle says that has been enough to get the attention of top coaches and players, at least prompting them to give it a spin and slide it in their bags. "Ultimately, the product has to work," he says. "Players and coaches are always looking for ways to improve. We like to use a lot the term 1% better every day and I felt this tool is one of those things that can help players improve and feel more confident."

Molle has relied on his hustle and word-of-mouth to spread the message and he's seen it used by Djokovic at Wimbledon, Medvedev at the Mouratoglou Tennis Academy, and a variety of top players from around the globe.

"The Saber has helped me work on my contact point and ensure that I'm hitting the ball consistently in the sweet spot," says Arthur Fery, Stanford graduate who has turned professional, "as well as being a fun tool to bring good variation to practices."

Molle says it is a special feeling to see so many players use it from the world's top players in singles and doubles to juniors and college players. The original Saber now has company. This year Functional Tennis launched a 265-gram Saber Lite version for younger players and plans to release a shorter junior version this fall. In 2023, Molle also created a 50-run limited edition colorway that coincided with the Australian Open, another run around Roland Garros and just released a third in time for Wimbledon. He has a fourth special edition planned to time with the U.S. Open.

"It's a productive, fun tool," O'Hare says, "that brings a positive spin to any practice session."