Madison Avenue has always viewed TV as something of a sure bet. This fall, however, fewer of TV’s biggest programs are making advertisers feel confident.

A Variety survey of commercial-ratings projections for the 2018-19 broadcast-network TV season finds that media buyers believe only a few top programs will build on audiences from last year. Among the programs they are betting on: NBC’s “Saturday Night Live” and a new run of “Thursday Night Football” games on Fox. Otherwise, media buyers predict so-called “commercial viewing,” also known in the industry as “C3” because it includes live viewership plus three more days of views, will fail to match live-viewing totals from last season for top-draw programming ranging from “Sunday Night Football to “Grey’s Anatomy.”

Commercial ratings are typically smaller than live viewership because they do not include that part of the audience that skips past commercials. Even so, comparing them to live ratings demonstrates the challenges networks will grapple with in weeks to come. Projections for “C3” are also smaller than those made in many cases for last season. One notable exception is NBC’s “This Is Us,” which buyers expect to exceed what they had estimated it would generate in the 2017-2018 season.

The Variety commercial-rating projections are culled by using estimates from three top media-buying agencies, which negotiate prices for and placement of billions of dollars in TV commercials each year.

Both “SNL” and “Thursday Night Football” have singular circumstances that could help drive projected gains. Since the end of its 42nd season, “SNL” has aired live across the country, starting at 11:30 p.m. eastern, creating a bigger linear audience for the venerable satire-and-comedy show. Meanwhile, “TNF” is about to start a new run under a five-year pact struck between the NFL and Fox. For the past two seasons, the league divvied up a run of Thursday-night games between CBS and NBC – and the match-ups were of lesser quality when compared t    o Sunday and Monday matches airing on CBS, Fox, NBC and ESPN.

The football predictions will no doubt be welcomed by the NFL. The average audience for a football broadcast in the league’s 2017 season came to 14.9 million, according Nielsen – a dip of 9.7% when compared with the average of 16.5 million viewers who watched a game during the regular season in 2016. Viewership of regular season games fell 8% the prior year. The Madison Avenue projection comes as the NFL continues to grapple with the cultural fallout of some of its players protesting police brutality and other social injustice issues during the playing of the national anthem .

Most TV programs continue to be judged based on the performance of Nielsen’s traditional audience ratings, which are widely referenced in the industry and in the media. In reality, however, advertisers’ focus has moved to the so-called C3 (commercial ratings plus three) measure. Since May 2007, sponsors and ad buyers have made the number of viewers who watch a particular show within three days’ of its on-air debut — and don’t skip through the ads – the basis for many of their commercial deals. The C3 rating became part of negotiations between networks and their advertisers as the rise of DVRs eroded viewership of programs – not to mention the commercials that interrupt them. In many cases, a measure known as “C7” that takes into account ad views for up to a week after an initial airing is the basis for pacts, and has become a new choice as streaming video and mobile devices spur even more time-shifted viewing.

Linear TV viewership continues to decline as technology allows couch potatoes to roll over to new screens to watch their video favorites. To be sure, thousands of people continue to watch “Empire” and “The Good Doctor” live as they air, but some portion of that group continues an inexorable exodus to streaming video and mobile devices.

These C3 projections should not be taken as gospel. The bulk of football ad pacts are based on live ratings, owing to the fact that only a sliver of the games’ audience time-shifts, though some buyers have suggested “C3” is used in some agreements. And simply put, there’s no guarantee advertisers will track viewership patterns exactly.

Other findings from Variety’s annual survey:

*NFL broadcasts continue to provide TV’s biggest crowds. Advertisers project NBC’s “Sunday Night Football,” Fox’s “Thursday Night Football,” Fox;’s “O.T” Sunday post-game show and NBC’s “Football Night in America” pre-game program will garner TV’s most sizeable ratings this season.

*NBC’s “This Is Us,” CBS’s “The Big Bang Theory” and ABC’s “The Good Doctor” are projected to be the scripted programs that generate the best “C3” this TV season.

*Advertisers have placed an unusual amount of confidence in the second season of ABC comedy “Splitting Up Together,” which just launched in March.

*Madison Avenue believes “The Conners” will be the best-viewed among TV’s freshman programs, followed by NBC’s “Manifest,”a mysterious drama about a planeload of people who find themselves fast-forwarded in time by five years; “The Kids Are Alright,”an ABC sitcom about a family navigating the challenges of 1973; and CBS’ reboot of “Murphy Brown.”

Here’s a comprehensive chart examining Variety’s C3 projections for the bulk of shows slated for the coming season. The scheduling for some of the programs have not been formally announced, but are based on buyer expectations. Mid-season programs are in italics.