Where is the NWSL successful? What could Boston learn from those cities?

Behind the spectacles in the stands lie lessons for Boston, which is getting another chance at professional women’s soccer with an investors group atop a list of potential NWSL expansion franchises to begin play in 2026.

Because it has teams in each of the four biggest professional leagues and fans with deep attachments to each of them, Boston is a different breed of sports town than San Diego and Portland, which have just one team each in the four big leagues. Still, whether it’s marketing, the stadium, the game-day experience, or the team on the field, the formula that drives success in San Diego and Portland bears relevance for Boston.

The person who sounds the least surprised that the Wave, in just their second season, have set NWSL attendance records is Jill Ellis.

Three months before the Wave played their first game at one-month-old Snapdragon Stadium in September of 2022, the team president urged the staff to aim high.

That meant selling out the stadium, which they did. The 32,000 who attended the team’s opener established an NWSL regular-season record.

“Nobody goes to the Olympics and goes, ‘Gosh, I really hope I win bronze,’ right?” said Ellis, who is best known as head coach of the US women’s national soccer team at the World Cups in 2015 and 2019.

“So I think we’ve just got to always push to the maximum of what we can achieve, because I also believe even if you fall short, you’re going to learn a hell of a lot more about taking risks and being bold in your thinking than you are by just planning conservatively and hitting numbers.”

The Wave, who drew close to 31,00 for their season opener this year, lead the league (and are ahead of 10 MLB teams) in average attendance with 21,545 — about 2,300 ahead of another new team, Los Angeles’s Angel City FC, and nearly 5,000 more than third-place Portland.

The move from 6,000-seat Torero Stadium at the University of San Diego late last season to Snapdragon, located just off I-8 north of the city and barely a half-hour ride from downtown on the trolley, validated the Wave.

“It’s a beautiful venue, it’s modern, the surface is fantastic — which for a purist like myself is really important — and the atmosphere there is such that the noise definitely comes down in volumes,” said Ellis. “Especially when you’re new to a town and you’re a new franchise, you want to make sure that that first experience is phenomenal because it’s an instant commercial for having people wanting to be back.”

Rachel Hill is a Wave forward from Rollinsford, N.H., who also played at the University of Connecticut. Before arriving in San Diego, she played for the Chicago Red Stars, the up-for-sale franchise that plays a 30-minute drive from downtown and has a firm grasp on the NWSL cellar for average attendance (3,874).

“We weren’t in the city of Chicago, and it was kind of a tough place to get out to,” said Hill. “There is nothing really around.

Hill added that Chicago was alreadya tough market to compete in because of the other major pro sports teams. The Wave, she said, “really do a great job of building that bond between the community and the team, and that’s another reason why the excitement is there.”

The Wave’s roster is blessed with the presence of Alex Morgan, arguably the top talent and most recognizable member of the national team. Attendance ticks up in other cities when she plays; New Jersey/New York Gotham FC set its attendance record (15,058) recently after advertising Morgan’s arrival.

The Wave have been building relationships with youth leagues and soccer fans south of the city, including in Mexico, where soccer is the national sport. They have pushed northward a bit, towards Orange, but they are well aware of Angel City FC, Los Angeles’s NWSL team that also began play last year.

The league at first expressed hesitancy about San Diego’s proximity to Los Angeles, but Ellis played it up as a rivalry the league needs.

“I think it’s going to be probably one of the purest rivalries in the league,” said Ellis.

San Diego’s supporters group, the Sirens, is, according to its president, “super open and welcoming.”

“You don’t hear as many snarky comments in our section,” said Tali Lerner. “We don’t take ourselves too seriously; I mean, we have a hippo and bubbles.”

On an evening when they could have been sunset surfing or pub-hopping in the Gaslamp Quarter, a sizable percentage of Sirens opted to attend this “Under the Sea” themed-game in aquatic garb.

Paul Nacu and his young son were wearing homemade orange-and-white-striped Marlin and Nemo T-shirts. Nacu believes that the Sirens and the Wave will eventually experience “exponential growth.”

“We’ll get more mainstream media, but right now there’s not as much as I’d like,” said Nacu. “You hear references to Alex Morgan on sports radio, not so much the wins and losses.”

Jeni Dell’s family didn’t recognize her when her soccer fandom began with the Wave’s entry into the NWSL.

“I never had a team I was passionate about, but I’m a huge advocate for women and women’s sports,” said Dell, the Sirens’ finance and events coordinator.

“Around nine months before the Wave came in, I saw on Facebook an announcement for a draft party for them and I was in. My family was like, ‘Who are you?’

“This is what I’m doing now. I’m on board. I’m going to the World Cup in Australia [next month] and I’ve got tickets to Paris for the women’s soccer Olympics [in 2024]. I went from 0 to 60. I fell in love with women’s sports.”

The Thorns have been the marquee franchise of the NWSL since their start as one of the original franchises in 2013. They won the league championship that first season, again in 2017, and are the current champions. No other team has won three titles.

Traditionally the league leader in attendance, the Thorns’ 16,000-plus average is higher than baseball’s Kansas City Royals, Miami Marlins, and Oakland A’s.

Portland, with its plentiful array of outdoor recreational and foodie options, is nicknamed “Soccer City USA” because of strong University of Portland women’s teams, vibrant youth leagues, and longtime support of the city’s Major League Soccer team, the Timbers.

At Providence Park, home to both the Thorns and Timbers, the Riveters support group unleashes its formidable rooting skills in the stadium’s North End.

Gabby Rosas, president of the board of directors of the 107 Independent Supporters Trust, parent organization for both the Riveters and the Timbers’ supporters group, Timbers Army, sees hope for a Boston team if it “figures out how to appeal to adults.”

“It’s not about trying to make it all kid-friendly,” says Rosas, “but putting together packages that try to make it be a little bit more mature. Let’s make this be a competitive sport where there’s swearing, there’s passion, there’s anger — it doesn’t have to be sanitized.

“I think especially in a city like Boston, which is not exactly known for being a calm sports town, it’s trying to figure out, how do people know that it’s OK to bring passion?”

Long before she became captain of the national team, Becky Sauerbrunn, now a defender for the Thorns, played in the summer of 2005 for the Boston Renegades, a second-tier USL team. She also played against the now-defunct Breakers at a couple of their Boston-area venues.

When told about the Boston bidders’ plan to help transform Franklin Park’s White Stadium to meet NWSL standards, the 38-year-old Sauerbrunn said, “Hey, as long as there are standards, that’s good. That’s a jump from the start of the NWSL, when I don’t think there really were standards.

“I don’t know who the owners are, but if they have deep enough pockets and they invest enough in the infrastructure, in the marketing, in introducing the team, then I think absolutely a women’s soccer team could thrive in Boston.”

She said the strategy of marketing only to soccer-playing families does a “disservice to a lot of other populations.”

“I think you can absolutely market us to everybody,” said Sauerbrunn. “Boston’s a little fickle, though; you guys are pretty hit-or-miss with your teams. If they do well, it’s great. If they do bad, everyone else messed something up, so it’s not their team’s fault.

“So their team has to be pretty good, right off the bat; I would say that would be helpful. And that comes down to putting in the right people — people that know the game, know women’s soccer, know the good players, know the environment.”

Shelby Hogan, a Thorns goalkeeper, grew up in Franklin and played for Bishop Feehan High School and Providence College, where her first season in 2017 was the Breakers’ last.

“It was obviously disappointing to see the Breakers fold back then, but I think there’s enough people for there to be a fan base,” said Hogan.

Start with youth, club, and college soccer fans, then gradually expand to Patriots, Red Sox, Celtics, and Bruins fans.

“It’s just how we bring them in and have them watch the product on the field and see how interesting it really can be,” said Hogan.

Thorns general manager Karina LeBlanc also has a Boston connection: She was a goalkeeper for the first version of the Boston Breakers in 2001-03.

LeBlanc challenged the question of whether an NWSL team can stand out and draw enough fans from a sports town like Boston where there is so much competition for fans.

“I guess my question to you is ‘Why do they have to choose?’ ” she said. “Sports brings life and energy to people, it brings purpose.

“Maybe you don’t have to be a season ticket-holder, but you can still support the team. Your core base of fans will come. They will buy season tickets, they will understand why they’re there, they’ll understand it’s part of something bigger.

“There’s room, there’s enough people in Boston. There’s room for everyone.”

Michael Silverman can be reached at michael.silverman@globe.com.