The NBA’s national television ratings are down double-digits compared to this time last year.

NBA on TNT viewership is down 22%, while NBA on ESPN is down 19%, according to Sports Business Journal. SBJ’s John Ourand does note there’s a “better local story” for the league because viewership on half of the local RSNs (regional sports networks) is up, but overall RSN NBA ratings are also down 7%.

So, what explains these declines?

Injured stars

Many onlookers are blaming it on injuries.

Kevin Durant, who signed with the Brooklyn Nets over the summer, is out for the season; Golden State Warriors star Klay Thompson is likely out for the season; Warriors star Steph Curry is out for the first three months of the season with a hand injury; DeMarcus Cousins, who joined the L.A. Lakers in the offseason, is out indefinitely; New Orleans Pelicans rookie Zion Williamson began his pro career with an injury in preseason, and is out indefinitely.

That’s five of the league’s biggest stars, not playing.

In fact, 64% of the games on TNT or ESPN (21 of 33 games so far) have had a star missing due to injury.

West Coast imbalance

Others say it’s a coastal issue: with LeBron James and Anthony Davis now both playing for the L.A. Lakers, and Kawhi Leonard and Paul George on the L.A. Clippers, the concentration of star power is on the West Coast. That means later game times, which means fewer East Coast fans staying up to watch.

Sports Media Watch, a handy sports ratings tracker site, points to these as the core factors along with the NBA schedule so far, writing that the ratings dip is “no mystery,” citing “injuries, competition and a weak schedule.” (Speaking of schedule, weak NBA on TNT games on Thursdays have been further hurt by competing with strong Thursday Night Football ratings.)

Broadcast vs. cable

Those are all basketball-related explanations.

In a broader context, the ratings (as well as teams sitting out star players to rest them, a newer trend known as “load management” that frustrates many fans) are prompting new discussions around the league’s broadcast strategy.

The New York Post and others suggest the NBA shorten its season to start closer to Christmas, as happened in 2011, the lockout year. Lo and behold, ESPN reported last week that the league is already in talks (likely in the works before this season’s ratings dip became a story) with the NBA Players Association and the NBA’s TV partners to make “sweeping, dramatic changes to the league calendar,” including reseeding the four conference finalists and shortening the length of the regular season.

Of course, less than six weeks into the season, it’s too early to panic about this season’s ratings. And the NBA has not commented publicly on the ratings.

But Dallas Mavericks owner Mark Cuban has.

His theory is that the NBA is seeing the fallout from putting the bulk of its games on cable (TNT, ESPN, and NBA TV) rather than broadcast (ABC). Cuban tweeted: “Ratings are down because all of our national broadcasts are exclusively available on cable, which is losing subs daily. Football benefits from being on broadcast tv which is in every digital and traditional package along with gambling available in some of the biggest markets.”

It’s not completely true that the NFL is on “every digital package” (streaming every NFL game without any cable package is difficult and pricey), but Cuban is right that the NFL has made far more of its content available over the top than the NBA has.

It’s worth noting that Cuban added, “On the flip side we help all cable broadcasters and distributors stay alive by keeping sports packaging alive, hopefully for the next 10yrs or more. Once it makes sense to simulcast streams in a low cost digital package, numbers will change.”

Competition from social media and streaming TV

There’s another possible explanation for the ratings dip, and it relates more to digital than to television: There are now so many places to find bite-sized NBA content and highlights (like Twitter, Instagram, Snapchat, and even TikTok, a partner of the NBA in China) that casual fans are less compelled than ever to sit down and watch a full regular-season game.

There is also more streaming content in general to choose from, which exacerbates the problem.

Anything that a person could watch on a given evening on cable or streaming—whether it’s sports or TV shows on Netflix, Hulu, Apple TV+, Disney+, or any OTT platform—is competition with NBA games for eyeballs. That extreme competition may hasten the need for the league to shorten its season.

[READ MORE: When will America hit peak streaming subs?]

Cuban commented on that issue, too: TV ratings, he tweeted, “don't capture the full commitment to a sport. Look at social media, YouTube/insta/snap/fb streams, live and highlights. They don't pay as much, but they are a reflection of demand for younger demos and global interest.”

Indeed, the consumption of all that digital content does reflect the popularity of the sport, but it may also be detracting from actual game viewership.

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Daniel Roberts is the sports business writer at Yahoo Finance. Follow him on Twitter at @readDanwrite.

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