Last season, ABC’s “Wicked City” was the first new broadcast show of the fall to be canceled, yanked after just three episodes. This season, no show looks likely to suffer that same disgrace. This fall’s disappointments instead appear destined to live out their initial episode orders as dead shows walking — not bad enough to cancel outright, not good enough to extend.

With ratings expectations evolving and hits harder to launch, broadcasters are practicing patience with underperformers. But that patience is creating a logjam. Many shows that were picked up to series ahead of upfronts are still waiting to be scheduled or have been pushed from winter to spring. The state of affairs reflects a new reality in broadcast.

“I have a lot of friends who have a lot of shows that are sort of sitting on deck,” says Peter M. Lenkov, executive producer of CBS’ “MacGyver” and “Hawaii Five-0.” “Nobody wants anybody else to fail, but the only way they’re going to get their show on the air is if something else fails. It’s hard.”

Failure has been redefined. Of fall’s lowest-rated new shows — ABC’s “Conviction” (0.8 live-plus-same day average Nielsen rating among viewers 18-49) and “Notorious” (0.9); and Fox’s “Pitch” (0.9) and “The Exorcist” (0.7) — none have been canceled. But none are expected to have their seasons extended beyond the initial episode order, much less renewed. “Conviction” had its order shortened in October from 13 episodes to 10.

As linear ratings have flattened in the era of digital and delayed-viewing, few shows, except for outliers such as Fox’s “Empire” and CBS’ “The Big Bang Theory,” draw numbers that rise above the crowd. And the crowd is growing. Faced with unprecedented competition from cable and streaming, broadcasters are ordering more new shows to feed viewers no longer willing to stomach reruns.

“Nobody wants anybody else to fail, but the only way they’re going to get their show on the air is if something else fails.” Peter M. Lenkov

“When you look at the linear ratings, that’s just a piece of the story now,” says Jeff Bader, president of program planning, strategy, and research for NBC Entertainment. “There are so many other factors involved, shows will not be pulled as fast as they used to be pulled.”

Among those considerations: Does the network own the show through its studio division? How does the show play internationally? On digital platforms? If a show draws mediocre linear ratings but generates revenue in later windows, the argument for keeping it alive is strong.

In years past, if a show was in the gutter by late October — particularly in the 10 p.m. hour, leading into local news — network executives felt pressure from affiliates to replace it with something more promising before Nielsen’s November sweeps. Now affiliate muscle has diminished, and sweeps are outmoded.

Networks have largely turned December over to holiday programming, live events, and specials. That leaves 10 to 12 weeks from the start of the season in September until the unofficial midseason break — enough time to run out a show that has been paid for but isn’t working; not enough time to successfully launch a new one.

As a result, shows that would be replacement material are being held in reserve, as networks endeavor to air original programming year-round. But as those reserves are pushed deeper into the season, their viewership and chance of making an impact are low. Talent also is affected, as actors in series with no path forward remain locked up until the official ax falls, unable to audition for other television projects.

For showrunners, the waiting game can be especially frustrating. The strictures of broadcast — creatively and in terms of the pilot process, which sees only a fraction of shows developed wind up on air — make it in some ways a less ideal platform for producers than cable or streaming. Long periods of uncertainty about when and if a greenlit show will be scheduled compound that.

“It’s very daunting, going into development, getting a pilot picked up, and then making a good pilot —where do they put it?” asks Lenkov. “The hardest part is finding the real estate.”