Ten years later, “Monday Night Football” is not the powerhouse it once was — and you cannot really blame it on the announcer Jon Gruden confusing viewers with his play-calling arcana. Viewership is down 17 percent to 10.7 million, and the decline at ESPN has continued in the two games after Donald J. Trump was elected president.

By contrast, NBC’s audiences increased in each of the two weeks after the election, cutting the season’s decline to 14 percent. But on Sunday, the viewership of 18.4 million for for Kansas City’s 30-27 overtime win over Denver tumbled 27 percent from last year’s Week 12 game.

Perhaps it was premature to think that Election Day would magically lift the cloud over N.F.L. ratings when so many other factors were also in play, such as the absence of a superteam, the national anthem protests, concerns about concussions and domestic violence and the early-season suspension of New England quarterback Tom Brady. In addition, the legal problems of the daily fantasy companies FanDuel and DraftKings have prevented those companies from focusing their customers’ attention on this season. The loss of millions of subscribers over the years to cord-cutters and internet services may also be hurting ESPN.

Saturation is another possible problem: Three windows of Sunday games, Monday and Thursday night games and a few early Sunday games from Europe may be more football than most people need. Pro Football Talk reported recently that the league was considering whether to reduce or eliminate Thursday games. Players and coaches have long disliked the short preparation time for those games, but the league enjoys the $450 million CBS and NBC are paying for them this season and next. A league spokesman denied the report.

There will, of course, be no reduction in Monday night games. So ESPN must endure a schedule that this season, for instance, features only one appearance each for Green Bay, Denver and Dallas, while NBC has three for the Packers and the Cowboys and four for the Broncos. NBC has yet another advantage: While teams can play on prime-time five times a season (four total on NBC and ESPN and one on Thursday night), three can play a sixth time — but all have to be shown by NBC.

“NBC’s advantages have been there since the deals were done,” Magnus said. “They’ve been a constant since the beginning.”