Attendance at ACC men’s basketball games, and in the 2011 ACC tournament game shown here, has dropped dramatically. (Streeter Lecka/GETTY IMAGES)

Wednesday night’s Duke-North Carolina game played out like a nationally televised infomercial for the drawing power of ACC men’s basketball. A delirious sell-out crowd was on hand at Dean Smith Center to see the hated Blue Devils stun the Tar Heels on Austin Rivers’s buzzer-beating three-pointer.

But such scenes in the stands have become increasingly rare in the ACC. With the college basketball regular season in its final month, nine of the conference’s 12 men’s basketball teams are on pace for a lower attendance from last year. Maryland and Virginia Tech both are averaging more than 1,500 fewer fans per game than this time last season, the two biggest drops in the league.

As a whole, the ACC is averaging 9,406 fans through Wednesday. It would be the lowest average for the league since the 1984-1985 season and the first time it has been lower than 10,000 since the 1988-1989 season. If those figures don’t drastically improve, it would be the fourth consecutive year the ACC’s attendance numbers declined.

Lee Ohanian, an economics professor at UCLA who teaches a course on sports business, said college basketball attendance throughout the country is down this season.

The Big East, for instance, is averaging 10,421 fans this season, down nearly 8 percent from 2010-11. But that conference saw attendance rise in every season from 2008-09 to 2010-11.

The ACC and Pacific-12 are the only leagues that have seen their attendance figures drop in every year since 2008.

“The [ACC] has to be concerned. As those types of numbers become more of a trend rather than a one- or two-year item, the league really does have to worry about that,” Ohanian said. “I would not be surprised if those programs have seen their winning percentage go down significantly.”

Wake Forest Athletic Director Ron Wellman, who has seen attendance at Lawrence Joel Coliseum drop by close to 50 percent since 2006, believes there are a number of factors, from the advent of high-definition televisions to an economy that’s still recovering from a recession to even the dates and times of scheduled games.

But he can’t ignore that perhaps it’s the play on the court that has also led to the downturn. After all, the Demon Deacons were ranked No. 1 in the country in January 2009, but have gone 19-37 the past two seasons.

“I think everyone recognizes that we’re not as competitive as we were a few years ago,” said Wellman, the ACC’s representative on the NCAA tournament selection committee. “We’re probably, in terms of depth in the conference, not as deep as we typically are. But heavens, if you look at the national championships the conference has won, nobody comes close to that.”

The ACC has won more NCAA titles than any other conference since 1981 (10), but eight of those belong to Duke and North Carolina. Not surprisingly, those two and Virginia — which this season got off to its best start since 1982-83 — are the only teams in the league that haven’t had their announced attendance fall so far (when comparing average attendance this season to average attendance on the same date last season).

A more accurate reflection of the league’s on-court performance may be Sweet 16 appearances. ACC teams made 30 appearances in the Sweet 16 during the 1980s and 29 in the 1990s.

But just 20 teams advanced that far between 2000 and 2009 even though the league expanded to 12 schools during that time.

Even Duke, which is the only ACC team to sell out every game this year, has been dealing with attendance issues. Last month, Duke’s student newspaper reported the school has been selling tickets in its famed “Cameron Crazies” student section to non-students this year to sell out the arena.

Maryland, which is looking into ways to boost revenue from the men’s basketball team to mitigate the athletic department’s financial woes, has seen its attendance fall every year since the 2007-08 season. At Virginia, attendance is slightly up from a year ago but is still down 18 percent since the 2006-07 season, when John Paul Jones Arena opened.

Virginia Tech, meanwhile, has drawn 1,615 fewer fans per game than this point last season, the biggest drop in the ACC. When the Hokies faced Florida State at Cassell Coliseum last month, just 7,256 fans showed up, a record low for a conference game since Virginia Tech joined the ACC in 2004.

An ACC spokesman declined to comment for this story because the league does not typically discuss attendance until the season is complete.

The conference’s attendance numbers have improved since ACC play began last month, but the three teams with the biggest arenas (North Carolina, North Carolina State and Maryland) each has only three home games remaining. Meanwhile, the two teams with the lowest average attendance — Georgia Tech (four home games remaining) and Miami (five) — have both played just 11 contests at home.

Wellman pointed to the turnover in the ACC’s coaching ranks as an explanation for why the league isn’t as good as it historically has been. Eight of the league’s 12 head coaches have been in their current position for three years or less.

“We recognize that it’s a little bit of a downswing right now, but it takes time to build a program the right way,” Wellman said. “If there’s a correlation between competitiveness of the overall conference, then the future of our attendance will be very positive.”

At Georgia Tech, attendance has dropped 50 percent since 2008. The school cited dwindling box-office numbers as a reason for firing former coach Paul Hewitt after last season. This year, Georgia Tech is averaging just 4,584 fans per game – 1,474 fewer than 2011 — as it splits time between two off-campus arenas while a new facility is being renovated.

The new arena, which will be in the same location as the old Alexander Memorial Coliseum, is seen as a “state of the art” project that will boost attendance figures, Georgia Tech Associate Athletic Director Wayne Hogan said this week. But he concedes his program’s problem at the box office is one that mirrors the rest of the ACC.

“We’re all facing the same challenges and we better address it as a league and individually,” Hogan said. “It’s not always about being able to roll a ball out and open our doors and people are going to come flooding in. I think you have to have a great product and I think you have to do some things around the product to entice people off of their couch.”