PHILADELPHIA >> If you overlook its pointlessly peculiar name, and the fact that it’s played with a modified Wiffle ball and a gigantic ping-pong paddle, you just might enjoy pickleball.

That is what millions of Americans have discovered. In the past three years, according to the Sports and Fitness Industry Association, the racket game has been the nation’s fastest-growing parti- cipation sport.

“It’s been sweeping the country,” said Jane Souewine, 65, who plays in a community league. “I’ve been amazed at how popular it’s become.”

Now that popularity appears to be accelerating as Americans cloistered by COVID-19 are increasingly pursuing social activities. In the Philadelphia area, residents of all ages, but especially seniors, are playing pickleball indoors and outdoors, in leagues and informal groups, on converted tennis courts and those built to satisfy the new demand.

A hybrid of ping pong and tennis, pickleball is played on a badminton-sized court, 44-by-20 feet. Using the paddles, participants serve underhanded, then smack the perforated, dense plastic ball back and forth across a net set at 34 inches.

Since the rules are simple and the physical demands few, much of its appeal is social. And because no special abilities or expensive equipment are required, almost anyone can play. Leagues tend to be as low-pressure as the sport’s funky name might suggest.

“It’s just a very fun two hours,” said Souewine. “It’s athletic. It’s social. It’s inexpensive. It checks a lot of boxes.”

Kate Corr, 60, said she plays doubles pickleball — by far the most common format — a few times a week with former tennis friends. The gatherings serve the same function that card parties or coffee klatches did in a more sedentary era.

“It’s a fun, social sport,” said Corr, a mother of six. “We bring a cooler of beer. If there’s more than four of us, we rotate in and out. If you’re sitting and waiting, you can have a cocktail. If you’re playing … you can still kind of chitchat and catch up.”

Pickleball’s pace tends to be slower than tennis or squash, and with a smaller court and a ball that travels at lower speeds, seniors and the unathletic can get their exercise without straining themselves.

“You don’t have to hit the ball as hard as in tennis, so you have a lot more long rallies,” said Jeremiah Thomas, 37, a onetime college tennis player whose serves in that sport were once measured at 142 mph. “It’s almost like chess. You can set up a point, react to things.”

The game was founded in 1965 when Joel Pritchard, a future Republican congressman, decided to play badminton with friends at his home on Bainbridge Island, Wash. When they couldn’t find a shuttlecock, they improvised with a Wiffle ball and homemade paddles. The story goes that while deciding on a name, someone spotted the Pritchards’ dog, Pickles, and the new sport was christened. But some claim the name actually derived from the rowing term “pickle boat,” in which a crew is assembled with oarsmen from different boats.

Though it’s decades old, pickleball’s popularity only recently gained momentum. Thomas discovered it in an online search after a devastating knee injury made tennis nearly impossible. Waks stumbled upon it at a community center, Souewine at an adult- education course.

Courts are popping up at tennis clubs, YMCAs, 55-and-over developments, public parks and private country clubs. Dozens of formal and informal leagues, like the whimsically named Garnet Valley Gherkins Pickleball Association, have been created to sate the growing appetite in Pennsylvania.

Thomas, who owns Camp Curiosity, a 50-acre site for children’s camps in Doylestown, Pa., has installed several courts there, both indoor and outdoor. Area leagues utilize them, and on occasion they’re open to the general public. Demand has been so great that he’s adding more.

“Recently, we’ve ordered a dozen more,” said Thomas. “We’ll have 17 outdoor courts ready to go by June.”

Greg Waks, an attorney who’s been playing for the past five years, said he’s had little trouble finding courts. He plays thrice weekly at a community center, and his condo has two private courts.

At a nearby park some courts are retrofitted tennis courts. “There are always tournaments,” he said.

An estimated 3 million people play pickleball, and thanks to large sporting-goods manufacturers, the game’s once rudimentary equipment has evolved. Today, for $200, you can buy a six-layer, carbon- fiber paddle.

There are three types of balls for the game. The indoor ball is lighter since there’s no wind, and its perforations are larger and more numerous, making it less likely to skid. The outdoor ball is heavier and more rubbery. Those used by elite players are made from a harder plastic.

Executives at PickleballCentral.com, a Washington state company that is the largest online seller of pickleball equipment, told the Puget Sound Business Journal that they expected revenue, estimated at $20 million in 2020, would grow by 25% this year.

“We started in September 2006 as a hobby website,” said Anna Copley, the company’s co-founder. “After three years the sport of pickleball was booming, and our little side business had grown into a full-time enterprise serving thousands of customers.”

Statistics show that 64% of pickleball players are, like Souewine and Corr, age 55 and over.

“It’s a sport anyone can play, even as you get older,” said Corr. “There’s not a lot of running. It’s more quick hands and hand-eye coordination. It’s not real tough on the joints.”

For those reasons, the game allows for more balanced competition between age groups than most sports. Thomas discovered that early in his transition to pickleball.

“I was playing this 65-year-old and he destroyed me,” Thomas said. “That really got me hooked.”