With fresh episodes of their top scripted shows running out and the midseason just around the corner, all the networks are at some risk, but NBC has the most to lose if the writers' strike goes into the new year and beyond.

The other broadcast networks are heading into midseason ready to roll out fresh new series, including a handful of promising reality shows, which should prop up ratings.

That's not the case for NBC. Its creative cupboard is close to bare, with no original episodes of hits like “Heroes” and "The Office” remaining and no new shows that are expected to generate big ratings.

Further, it will go into the midseason already in fourth place in the 18-49 demographic and without its No. 1 show, “Sunday Night Football,” which will wrap up early next month.

The likely outcome: NBC’s ratings, already down 11 percent in 18-49s from last season, will tumble further.

“When they go into strike contingency plan, they’re at high risk,” says Susan Hajny, broadcast research manager at GSD&M.

“One big problem for NBC is that it has no big promotional platform to entice viewers to shows they’ll have to plug in. They’re going to lose football, so they don’t have any other big ratings. Also, they don’t have any new-show buzz to entice people watching repeats somewhere else.”

The best NBC will have to offer at midseason are returning shows like “The Biggest Loser” and the drama “Medium,” which generate only modest ratings. It also has "Law & Order" and "Law & Order: Criminal Intent" returning back to back Wednesdays.

Its one notable new show is the Brooke Shields drama “Lipstick Jungle,” premiering in February to fill in for “ER.”

Also returning are the reality shows “Singing Bee,” a celebrity version of “The Apprentice” and game show “1 vs. 100.” Among its new reality shows are the short-run “Clash of the Choirs” and "American Gladiators," but neither are expected to do well.

That leaves NBC in a sticky position.

More than the other networks it will rely on repeats, and NBC shows do not repeat very well. Its 18-49 rating for repeats last season was 29 percent lower than for originals, according to buying agency Magna Global.

It also must fill four hours on Sunday to replace football, which it will do with reality programming.

“The choice for them is going to be repeats and they have all that sci-fi stuff that, to a certain extent, is serialized, which doesn’t repeat well,” says David Scardino, entertainment specialist at Rubin Postaer and Associates. “Or they are going with untried reality and, in the case of ‘American Gladiators,’ revived reality.”

“They’re in pretty poor shape,” says Shari Anne Brill, senior vice president and director of programming at Carat. “Their backup is too reality dependent and, with the exception of ‘Deal or No Deal,’ their [unscripted shows] aren’t big players.”

NBC has only a few scripted shows with more than a few unaired episodes, including the low-rated like “Friday Night Lights” and aforementioned “Law & Order.”

Yet another worry facing the network is that it by going into reruns it will miss out on the substantial kickup in ratings hit shows like “Heroes” and “Office” get from DVR playback. Viewers aren’t going to record shows they’ve already seen.

“They have more shows than anybody else that have major time-shifting,” says Hajny. “They have seven shows where more than 25 percent of their full seven-day program rating is due to time shifting. Three of those shows approach 40 percent, which tells me these [viewers] are fans who’ve caught every episode. If NBC has to run repeats, those ratings are going to plummet.”