The Cleveland Cavaliers, headed by generational superstar LeBron James, are currently in a playoff dead heat with the Boston Celtics. The series, which will climax with a decisive Game 7 on Sunday, has generated the highest ratings for an NBA Eastern Conference semifinal since 2014, including a Wednesday game that drew 7.35 million viewers.
That’s a sharp contrast to ratings for last season’s NFL playoffs, which dropped by as much as 16%. The NFL’s dramatic decline has been blamed on factors from brain injury and domestic violence controversies to, most recently, a thorny fight over players’ right to protest during the National Anthem. The NFL’s announcement this week that it would effectively ban players from kneeling during the Anthem seems sure to propel controversy well into next season, and maybe further depress ratings.
Those contrasting narratives demand an assessment. Football is Americans’ favorite sport by far, but basketball, second most popular, seems poised to surge. Is there any chance basketball could take the top spot a few years down the line?
More from FORTUNE
Get Data Sheet, Fortune’s technology newsletter.
At first glance, that looks like a longshot. According to Gallup, Football still overwhelmingly dominates American enthusiasm, with 37% calling it their favorite sport, compared to 11% for basketball (baseball is at 9%, after decades of declining stature).
But that survey doesn’t reflect actual viewership or fans’ willingness to spend. NFL and NBA ratings aren’t easily comparable, since there are far more games per season in the NBA than in the NFL. In terms of each sport’s peak, it’s hard to imagine an eclipse for the Super Bowl, one of a dwindling number of moments when Americans all seem to be talking about the same thing – attention advertisers are glad to pay generously for.
Overall revenues might be a better metric, and though that’s still somewhat opaque, it’s where the NFL’s weakness is most obvious. NFL revenue grew an estimated $900 million to $14 billion in 2017, or just short of 7% growth. Forbes, meanwhile, reports the most recent NBA season generated $7.4 billion for teams, up a staggering 25% from the year before.
That suggests the NBA is growing more than three times as fast as the NFL – and that could have startling impacts in just a few years. Using the most basic sort of growth calculation, current trends point to NFL revenues of around $28 billion by 2029 – about in line with a goal of $25 billion by 2027 Commissioner Roger Goodell set a little over a decade ago.
But the same calculations using the most recent growth numbers suggest that by 2029, NBA revenues will be – brace yourself – over $68 billion.
Now, those aren’t projections based on detailed models, and the nature of TV contracts means revenue can be an imperfect measure of overall trends. The NBA’s huge 2017 growth was probably a one-time surge – growth was a little over 13% in 2016. But even at that lower rate, the NBA would close most of the gap with the NFL over the next decade.
And intangibles also suggest things are trending the NBA’s direction. The NBA has been propelled in part by a deep bench of charismatic megastars including not only LeBron, but the Houston Rockets’ James Harden and the Golden State Warriors’ Steph Curry. The NFL’s biggest names – including Tom Brady, Cam Newton, and J.J. Watt – arguably tend to be older or lower key. And, the NBA has much stronger ties to popular culture, especially hip-hop.
Then, of course, there’s #takeaknee, a movement intended to protest police violence against African-Americans, who make up about 70% of NFL rosters. The protest movement wasn’t destined to harm the league, but mixed messages from owners and other leaders arguably made things more contentious. President Trump didn’t help when he called for a boycott of teams whose players protested. Now there’s a matching call on the other side, with a growing petition pressuring advertisers to boycott the league after its protest ban.
That adds up to a worst case scenario, in which a sport ostensibly intended as escapist entertainment becomes a proxy for America’s broader political and cultural divides. If the situation doesn’t change, it could erode the NFL’s self-proclaimed status as America’s Game – and give the NBA the chance to take that crown.