Week 15 featured a broadcast anomaly that helped the NFL secure a massive combined audience on Sunday afternoon.

For the first time this season, Sunday afternoon’s NFL slate featured a “double-doubleheader” in which both CBS and Fox air competing national window games in the 4:25 p.m. ET window. This happens twice a year, but only recently has the NFL opted to place one of these double-doubleheaders in the middle of the season. Initially, CBS and Fox would each air competing national window games in Weeks 1 and 18. But the past two years, the NFL has opted to remove the double-doubleheader from Week 1, instead giving CBS and Fox an opportunity to secure massive audiences for themselves rather than competing against one another.

That has pushed one of these double-doubleheaders to the middle of the season. And Sunday afternoon was the perfect storm, with several high-interest early-afternoon games leading into a late-afternoon slate featuring the Green Bay Packers-Denver Broncos game on CBS, and the Detroit Lions-Los Angeles Rams game on Fox.

According to press releases issued by both networks on Tuesday, Sunday’s late-afternoon window averaged a combined 43.9 million viewers between CBS and Fox. Last year’s mid-season double-doubleheader, the first of its kind, averaged 39.6 million viewers, meaning Sunday saw an 11% year-over-year increase for the league. The Broncos’ win over the Packers averaged 24.5 million viewers on CBS, while the Rams’ win over the Lions secured 19.4 million viewers on Fox.

“NFL ON CBS” Scores its Most-Watched Week 15 Doubleheader Ever
🏈GB-DEN at 4:25 PM: Most-watched program of the week on any network with 24.497 M viewers
🏈NE-BUF and LAC-KC at 1 PM: Best Week 15 regional window on any network in 37 years with 18.926 M viewers

Record-Setting… pic.twitter.com/ybLKnhuN2U

— CBS Sports PR (@CBSSportsGang) December 16, 2025

With #NFLPlayoffs on the horizon, @NFLONFOX delivers 19.4 million for its Week 15 AMERICA’S GAME OF THE WEEK window, highlighted by the Rams victory over the Lions 📈 pic.twitter.com/orm0JMQx3o

— FOX Sports PR (@FOXSportsPR) December 16, 2025

CBS benefited from an exceptionally strong 1 p.m. window, averaging 18.9 million viewers for regional action featuring two dandies: Bills-Patriots and Chargers-Chiefs. Both games went down to the wire, and both had massive playoff implications. Fox, on the other hand, averaged just 9.5 million viewers for a much more underwhelming lineup that featured Raiders-Eagles or Browns-Bears in most markets. Still, the network was able to surge by 10 million viewers for its national window, despite direct competition from CBS.

Sunday shows the power of the double-doubleheader, and why the NFL likes them so much. Rather than a single network earning 20-some million viewers, the NFL gets to benefit from two networks putting up gaudy numbers. 43.9 million viewers is in the same ballpark as the NFL’s Thanksgiving day audiences.

CBS and Fox hate the double-doubleheader, for obvious reasons. They’d rather secure a bigger audience for themselves and not have to compete with another game.

A result like Sunday’s might make the NFL rethink the number of double-doubleheaders it adds to the schedule, however. If there’s more juice to be squeezed from the viewership lime, the NFL will usually find a way to squeeze it.