What makes a tennis court?

Sure, it’s got something to do with the quality of the net. Whether or not there are cracks in the playing surface; how the ball responds when gravity pulls it to the ground. Does it pop? Or slide? Something in between?

What really makes a tennis court is the people who play on it: the people, often, who are allowed to play on it. Is it members-only? Reserved for local residents? Accessible only to those with enough cash in their leisure account?

Or, can anyone bring their rackets?

This is the way it is on Pompey Park in Delray Beach, Florida, and that goes a long way toward explaining Coco Gauff — and the success of American tennis, especially among its women — over the years.

(Photo of Pompey Park: Scott McIntyre for The Athletic; Map: Drew Jordan for The Athletic)

Pompey Park is nothing special in the lexicon of epic tennis courts, in the U.S. or anywhere. This is not the storied grass of Longwood Cricket Club near Boston. Other than the color of the courts, Pompey Park has nothing in common with the behind-the-gates exclusivity of the Los Angeles Tennis Club, where Fred Perry and Don Budge played for the pleasure of Clark Gable and Marlene Dietrich.

(Scott McIntyre / For The Athletic)

The two recently resurfaced courts in Pompey Park are tucked into the Northeast corner of the sprawling property. You are roughly a mile from the ocean, but edging toward the far less fancy part of town — near Interstate 95 and the railroad tracks. Off in the distance, there are some baseball fields, some basketball courts, some grass and some shade trees.

It’s a sweet place to start a day, which is what Gauff, and her father, Corey, did so often during her earliest years. The years when she was just an athletic elementary school kid trying to find a sport.

“I’ve played there since I was six years old,” said Gauff, who grew up about a five-minute ride from Pompey Park. “It’s free public courts.”

(Scott McIntyre / For The Athletic)

Tennis may never shake its reputation as a country club sport, a pastime for the wealthy. And yet there are roughly 270,000 courts in the U.S. for about 24 million players, and about 70 percent of the country’s tennis gets played at public facilities.

Still, there are public facilities and then there are public facilities. Some come with fees and registration rules.

Then, there are the places like Pompey Park. First-come-first-serve, stay as long as you like or as long as you can stand the heat and humidity of south Florida. Hack away, gossip between points, or train to become the next great American champion.

(Scott McIntyre / For The Athletic)

It’s the sort of environment that Americans can sometimes take for granted. The tennis boom in the second half of the 20th century spawned the construction of many courts in many parks and at many schools all across the country. And it’s how the Williams sisters, Gauff, and last year’s Wimbledon junior champion, Clervie Ngounoue, got their start.

(Scott McIntyre / For The Athletic)

As the kids say these days, it’s not that deep. But that is not how it works in a lot of places.

“I’m a little surprised we’re able to play here for free,” said Laszlo Fekete on a weekday morning.

Fekete and his wife, Barabara, were in Florida from Norway, where he said playing tennis generally requires club membership and paying for court time. They are tennis nuts.

They brought their rackets on vacation to Florida, and when Laszlo reached out to a local pro on Instagram, she recommended they meet at Pompey Park, where they could swing in the late morning, when the locals began to hide from the heat, to play as long as they liked. That was the day before. The Feketes were so taken with the concept that they were back 24 hours later

That’s what Gauff and her dad used to do, before school and after, and for huge chunks of the day on weekends. It’s not like it’s all they could do. Delray Beach also has a massive tennis center, not far from Pompey Park. It even hosts a small ATP Tour event each February.

There are plenty of tennis programs there, with plenty of coaches who will run clinics and wax on about proper form. At the beginning, the Gauffs took a pass on all that.

(Scott McIntyre / For The Athletic)

“Just the easiest thing, just go on the public courts and play,” she said.

And they knew Pompey Park was the place. Her family has a little history there.

Go back just over half a century. Florida is a different sort of place. Black kids are not exactly welcome in the youth baseball leagues.

Gauff’s grandmother, Yvonne Lee Odom, who was among the first Black students to integrate the city’s public schools, and her grandfather, a former minor league baseball player named Eddie “Red” Odom, who worked in the local parks department, decided to do something about that.

(Scott McIntyre / For The Athletic)

They founded a Little League for Black kids, which is based in Pompey Park. The big baseball field, off in the distance, a few hundred yards from where Gauff was banging her first balls over the net? That’s Odom Field now, her grandparents’ name in big block letters on the scoreboard.

Gauff has known how important her parents’ lives were to the people of her hometown, and to the kids who play in that park since she was a small child. She knows too how important it was that she got to play there.

“It wasn’t randomly chosen by any means,” she said.

There’s another sign now. It’s on the gate to the tennis courts, explaining that the courts were resurfaced with a grant from the U.S. Tennis Association.

(Scott McIntyre / For The Athletic)

“In honor of Coco Gauff 2023 U.S. Open champion,” it says.

It’s way smaller than the one with her grandparents’ name on it, overlooking that baseball field a few hundred yards away. She’s just fine with that.

(Top photos: Scott McIntyre; Getty Images; Design: Eamonn Dalton, Drew Jordan for The Athletic)