The sound of pickleball is impossible to ignore.

It's different from the rounded pop of a tennis ball, or the elastic thud of a racquetball as it hits the wall. Instead, it's the sound of a Wiffle ball and paddle coming together, a collision of plastic: whack, whip, whop.

It's a sound reverberating across the west metro, where suburbs are hurrying to meet the growing and vocal demand for more outdoor pickleball courts.

Cities are entering what Eden Prairie recreation supervisor Bob Lanzi likes to call Phase 2 of the fever, as parks and recreation departments move from retrofitting gyms or tennis courts for pickleball to building permanent facilities actually designed for the game.

Officials in Bloomington, Minnetonka and Eden Prairie recently approved construction of eight new pickleball courts at local parks, and Hopkins is adding five courts at Central Park. The outdoor courts are expected to open this summer, city officials say.

City officials, who long have heard the clamor for more courts, are confident that if they build them, players will come.

"There is just tremendous explosion in the sport," said Dennis Gallaher, president of the Southwest Metro Pickleball Club, which over the years has grown to more than 535 members. "It's going to just keep exploding."

Pickleball is an amalgam of established racquet sports, with an entirely unique scoring system and set of rules. The paddle is rectangular, and the ball, though plastic, bounces in play. Courts are small, separated by a net striped with different areas of play, including non-volley zones on each side.

Games are usually played to 11 points, although some larger groups play to 7 to speed up player rotations. Like tennis, the ball is served to the other side, and players volley back and forth until one side wins the point.

Pickleball is particularly popular among older adults. About 75 percent of regular players are 55 and up, according to the USA Pickleball Association. Many of them made the switch to pickleball from tennis or racquetball, which require more stamina and often run a higher risk of injury.

Pickleball players can remain active for years with little risk of injury, said Catherine Turner, a local pickleball instructor.

"We don't want to run that far playing tennis anymore, and this is so much like tennis," said Turner, 69. "It's something we can do way into our 80s."

The game's growing popularity seems to correlate with the state's aging population. The number of adults 65 and older, often defined as seniors, is expected to nearly double between 2010 and 2030, according to Minnesota Compass, a nonprofit that tracks state trends. Hennepin County is aging faster than most counties and is expected to have more than 240,000 seniors by 2030 (the number was about 135,000 in 2010).

Turner first heard that pickleball sound three years ago while she was teaching a Zumba class at a community center.

"It sounded like a tick tock, tick tock," she said. "I was hooked in five minutes."

'Hit 'em hard'

Although the response of the suburbs to the demand for pickleball courts has recently accelerated, the popularity of the sport is nothing new.

It dates back to 1965, when Joel Pritchard, a Seattle native who went on to serve in Congress, improvised the game with some friends. According to Pritchard's wife, they named it after the "pickle boat," the last fishing boat to return with a catch hauled in by a crew assembled from leftover rowers. Similarly, pickleball players rotate through multiple rounds.

They show up at tournaments by the hundreds; Arizona and Florida, both of which have significant senior populations, are international hotbeds.

The communal devotion to the sport has assumed the form of a cult following, like Grateful Dead fans bonding over their favorite bootleg recordings. Players call themselves pickleball nuts, even addicts. Once you play, they say, you won't be able to stop.

"There is a tremendous camaraderie among players," Gallaher said. "It just makes the sport a joy."

The Eden Prairie Community Center offers pickleball three times a day along with drill sessions and clinics, Lanzi said. He said the game is played by people from ages 7 to 77.

"You have a lot of … born-again jocks," said Lanzi, 59, who used to play competitive racquetball. "You start playing pickleball and your eyes light up because you get a new lease on life."

The Southwest Metro Pickleball Club had a lot to do with the growth in new courts, Gallaher said, with dozens of members lobbying city officials and showing up at council meetings.

"You have to hit 'em hard," Gallaher said. "I think they're starting to realize that this sport does require facilities."

'Significant investment'

Hopkins is spending about $262,000 on its five courts, while Minnetonka has a $410,000 budget for its eight courts. Eden Prairie's new facility will be part of a $426,000 renovation of Staring Lake Park, which includes renovation of its tennis and basketball courts.

Jay Lotthammer, Eden Prairie's Parks and Recreation director, said the new courts are a "significant investment" by the city. He expects them to be heavily used this summer.

"The amount of use [at the community center] really communicated that it's a good value," Lotthammer said. "There's no question that they will be well used."

On a recent afternoon, dozens of pickleball players, paddles in hand, rushed the two courts at the Hopkins Activity Center for their chance to play.

Most were seniors or retirees who had the time to play for a couple hours during the middle of the day. They sat in a row against the wall, waiting for their turn as others teamed up for doubles games.

Barb Horgen, 67, learned the game in 2011. She has played ever since, even as joint disorders and other medical issues led her to don knee braces. When she broke her foot and hip a few years ago, she showed up to play in a wheelchair.

Pickleball is a fun way to socialize as well as exercise, she said. She is the Hopkins Center's de facto "PPP" — Pickleball Party Planner — who organizes picnics, birthday celebrations and gatherings at the nearby Wild Boar Bar and Grill.

"It's a great thing for older people to get out and socialize," she said, calling pickleball "a fun thing instead of a competition thing. At least here it is, anyway."

But Horgen does employ one trick to improve her chances of winning: a pair of hot-pink Converse sneakers. "I got these so I could distract them," she said.

Miguel Otárola • 612-673-4753