By Michael Hurley, CBS Boston

BOSTON (CBS) — The NFL’s ratings decline is no joke. The league has a serious viewership problem on its hands.

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Ratings dipped dramatically in Week 9 when compared to last year, with the prime-time Broncos-Raiders Sunday Night Football matchup dropping 20 percent, as reported by Austin Karp of Sports Business Daily.

The numbers on the Sunday night game, in particular, should be concerning for Roger Goodell and the NFL owners. It was a prime-time matchup that featured the defending Super Bowl champions (albeit without Peyton Manning) against an up-and-coming team with the best young quarterback in the NFL. There was no World Series game competing with it, and the game itself remained competitive throughout, as the Broncos kept the score within one possession for the bulk of the evening.

Nevertheless, the ratings weren’t there, and the drop-off from last year’s Eagles-Cowboys game in prime time in Week 9.

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Karp noted that the breaking news regarding the FBI finding nothing new in the most recent batch of Hillary Clinton emails likely worked to draw viewers away from the afternoon slate of games on CBS and Fox.

The 4:15 p.m. national window on CBS featured the Colts beating the Packers in Green Bay, though ratings for that game were down 20 percent from last year’s Week 9 matchup between the Broncos and Colts.

While the soap opera-level of intrigue with the election has no doubt stolen some eyeballs from people who might otherwise be watching football, and while the protestors of Colin Kaepernick’s protest remain a vocal group, the common denominator among all of the ratings drops this season is easy to see: bad football. And while Sunday night’s game wouldn’t fall under that category, it’s possible that the cumulative effect of having the Chicago Bears on prime time four times in the first eight weeks and of having Jaguars-Titans and Dolphins-Bengals and other dismal “Color Rush” games every Thursday has dampened enthusiasm for the NFL product.

And, as @SportsTVRatings chronicles regularly on Twitter, other sports remain unaffected by the election or any other at-the-ready excuse for the NFL’s falling ratings. Just this past weekend, ESPN posted a 42 percent uptick in its Friday night doubleheader. And it’s not just a specific issue with the sport itself, as college football ratings have been strong this fall.

Of course, it’s important to keep in perspective that the NFL is still king among American sports in terms of TV ratings. While the World Series involving the Chicago Cubs breaking a 108-year championship drought did indeed draw very strong ratings, the reality is that the other three major American sports would love to have a midseason matchup draw an 11.7 rating like the NFL just did on Sunday night. So while the NFL’s current ratings drop may well represent a problem, it’s not nearly a “crisis.”

Still, considering the league’s once-bulletproof reputation for being an unstoppable ratings juggernaut no matter the circumstance or matchup or time slot, addressing the problem will no doubt move to the top of the list of every owners meeting from now until the ratings start to turn the other way.

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For the first time in a very long time, the NFL’s executives and owners are going to have to get creative to entice people back to their product.