SAN JOSE — Before a recent Sharks game at SAP Center, the crowd was treated to a video montage of great moments in team history: huge regular season and playoff goals, thunderous hits and flashy saves, all done by some of the best and most popular players ever to wear teal, all played before sold-out, high-octane crowds.

Then the lights came on, and the contrast was stark: scores of empty seats and a corresponding sound.

Where did everybody go?

“You’ve got massive sections just not even there. You’ll see two people in a row,” said Michael Kriegbaum, a Morgan Hill resident and a season-ticket holder for the team’s entire 25-year existence. “It’s kind of surreal, because it’s been solid for so many years, and there’s just no energy.”

Since their beginning in 1991 at the Cow Palace, the Sharks have been one of the NHL’s shining examples of how hockey can work in a nontraditional market. They had a five-year streak of sellouts, 205 games overall. For a span of nine seasons, starting in 2006, they played to 99.8 percent of capacity at their 17,562-seat arena. Just once in franchise history — in 2003-04 — did average home attendance fall below 96 percent of capacity.

This could be the second season.

Through six games, average attendance at The Tank is 16,068 — or 91.5 percent of capacity, a percentage that ranks 21st out of 30 teams in the league. There has been only one sellout — the home opener. A game against the L.A. Kings fell short of a sellout. A game against Nashville drew 15,219, the smallest crowd for a game since 2006. And those are paid-attendance figures. The number of people in seats is actually smaller.

Behind the decline is a steady erosion of season-ticket sales.

Three years ago, the Sharks had about 14,000 season-ticket holders. That number now is between 11,000 and 12,000, according to Sharks COO John Tortora.

The decline began in 2014. After the team’s epic playoff collapse against the Kings, season-ticket renewals fell to 89 percent. Last year, after the Sharks missed the playoffs for the first time in 12 years, the number fell to 85 percent.

Bottom line: With fewer season-ticket holders, there are more seats available for every game, and the Sharks haven’t been able to sell all of them.

The on-ice performance of the team last season — 40-33-9 overall and 19-17-5 at home — was a headwind. But some business moves by the team also ruffled feathers.

Season-ticket prices for this year increased from 3.7 percent for one upper bowl area to 8.2 percent for a handful of seats along the glass. The cost of a season ticket in 2014-15 ranged from $26 to $206 per game. This year it was $28 to $222. The increase is small — between $2 and $16 — until you multiply it by 41 (the number of games) and then double the grand total (presuming you don’t plan to go alone). Then the increase is between $164 and $1,312.

Beyond economics, some fans were put off by a change in the deadline for season-ticket renewals. Typically, the deadline was late May-early June. Last year, it was moved up to March, although the Sharks reduced the down payment to 10 percent.

Parting ways with popular television announcer Drew Remenda and the introduction of the Sharks’ Ice Team were also moves that initially rankled the fan base.

“If it isn’t broke, don’t fix it,” Nik Rode of Berkeley, a season-ticket holder from 2010-2013, wrote in an email. “The last few years have felt like the Sharks organization doesn’t care about me as a (season-ticket holder), or a fan in general.”

The Sharks are rethinking how they engage their fan base.

“The world has changed. The whole way you sell tickets is different from what it was five or 10 years ago,” Tortora said recently. “When we were renewing at 92-93 percent, perhaps the need to sell wasn’t as great as it is when you’re not renewing at those levels.”

The Sharks are holding more promotions now than in recent seasons. They have added staff to specifically cater to season-ticket holders. On this homestand, season-ticket holders were offered two additional seats to a game, free of cost.

“Those are some of the things that we probably haven’t done as well as we could have in the past,” Tortora said.

But nothing works like winning. If the Sharks, 7-6 after a 4-0 start, don’t win, the building won’t be full.

“There’s still Sharks fans out here, that’s for sure,” said defenseman Marc-Edouard Vlasic, whose 10 years with the team have been marked by mostly sellout crowds. “But I guess year after year, if you lose in the playoffs and then don’t make the playoffs, maybe that’s what happens.”

Cathy Ferrari of San Jose, a season-ticket holder since the inaugural season in 1991, did not renew this year. It was mostly an economic decision, she said. She and her husband had always been able to offset the cost by selling the games they couldn’t attend.

Last year that changed.

“We couldn’t sell them,” said Ferrari, whose seats were $104 apiece. “Sometimes we couldn’t give them away.”

Brian Ricks of San Jose also found that selling tickets online last season was tough. Now, he and his father are “on their last legs” as far as keeping their season tickets.

He said when they first came on board in the Cow Palace days, tickets were just over $30 per game. Now their upper bowl tickets are over $60 per seat for a team that no longer is a slam-dunk to make the playoffs.

“It’s almost $6,000, and it just doesn’t seem worth it for us,” Ricks said.

He added that the Sharks would do well to step up their in-game production to match other NHL teams.

“I’ve gone to a couple of L.A. Kings games at the Staples Center, and it’s like a show,” Ricks said. “It’s a fun time. For the Sharks during the breaks, it’s ‘insert paid sponsorship thing here’ and that’s it.”

Tortora knows some fans are frustrated, and he said the Sharks are taking steps to address that. He doesn’t anticipate attendance being a long-term problem.

“It’s going to ebb and flow,” Tortora said. “We’re still at 90-95 percent capacity, our renewals and our season-ticket revenue overall remains in the top half of the league. So we’re doing quite well, although we have some improving to do.”

For more on the Sharks, see the Working the Corners blog at blogs.mercurynews.com/sharks. Follow Curtis Pashelka on Twitter at twitter.com/CurtisPashelka.