The NFL adopted the flex rule prior to the 2006 season. It allows the league to change out less appealing prime time matchups later in the season in favor of games that have become more important than anticipated when the season began. When it was first introduced, the flex rule could only be used from weeks 10-15. In 2014, the NFL adopted a provision that would allow the league to use the rule as early as week 5.
The San Francisco 49ers and the Los Angeles Rams are the earliest victims of the flex rule in league history. Since Jimmy Garoppolo went down with a torn ACL, the 49ers have become less intriguing in the national landscape. That game moves out of NBC’s Sunday night slot for week 7 and onto CBS’s 4:25pm slate. The Cincinnati Bengals and Kansas City Chiefs will take over as the primetime game.
The networks bet big on the 49ers before the season began. The league scheduled the team in primetime 5 times in the 2018 season. The 49ers have suffered blowout losses in recent weeks, and the NFL saw a potential ratings disaster looming in what has been a season full of positive ratings news.