Like teenagers, backpacks slung on one shoulder, reluctantly trudging off to a new school year, the broadcast networks resume their own odd autumn ritual today. It's Premiere Week.

The Big Four, with The CW following suit in October, have packed their primetime schedules with new and returning series to duke it out — all in hopes of grabbing the increasingly hard-to-woo live audiences. Each new entry will launch with lofty expectations of becoming the next This Is Us. Then, the following morning, we'll all pretend that night-of viewing doesn't matter anymore, even though it can still be pretty damn indicative of what's going to work and what's going to quietly evaporate before the new year.

It can feel beyond anachronistic in the age of Peak TV, 450-plus original U.S. scripted series seemingly airing in unison on umpteen platforms, but there are still merits to Premiere Week. For one, it answers a lot of questions that have been gestating since May's big pitch to ad buyers at the upfront presentations. It is broadcast's annual physical, gauging what series are still healthy, offering a prognosis of potential trends and reminding the industry that, while not all numbers are where they should be, things could be a lot worse.

So what do we want to know? Looking at the week and months ahead, these are the pressing questions whose answers will shape the narrative of the 2017-18 broadcast season.

Just how patriotic are American viewers feeling these days?
Nearly three years after the surprise box-office dominance of American Sniper, entertainment's military trend is set to hit the saturation point with three (three!) soldier-centric series joining the schedule this fall. NBC's The Brave, CBS' SEAL Team and The CW's Valor all arrive in the coming weeks — none of them expected to do particularly well in other markets. And while the likelihood of each entry achieving hit status is unlikely, just one breaking through will ensure patriotic procedurals staying part of the conversation for at least another year.

When is it time to worry about the NFL?
If football's 2016 ratings dips raised eyebrows, early losses for the 2017 season are likely prompting queasy stomachs. The first two weekends of NFL brought double-digit ratings losses from the previous year, a fact that could have repercussions far beyond finances for the heavily invested NBC, CBS and Fox. Smaller football audiences mean less of a marketing reach for new series, and significant losses could alter broadcast rankings — which, while a little archaic at this point, still fuel PowerPoint presentations and press releases.

Will the latest spinoffs be a success?
If there is a shining hope for the fall schedule, it is CBS' Young Sheldon. Early reviews are generally positive, and it's a prequel to the most dominant broadcast series of the past decade. But is season 11 really the right time to launch a Big Bang Theory spinoff? Sure, it's still the highest-rated show on broadcast, but the iron has certainly been hotter. And speaking of spinoffs, Fox really didn't position last season's Star as anything more than another Lee Daniels creation. The conversation around the drama has decidedly shifted, now that it's paired on Wednesdays with sister series Empire. Any doubt that Star is a spinoff of Fox's No. 1 show goes out the door with the Sept. 27 crossover — a clear attempt to lift Star's less-than- stellar ratings.

Can This Is Us maintain its momentum?
There is no TV cliche with more truth to it than the notion of a "sophomore slump." For most instant hits, either critically or commercially, the second year can be particularly difficult. So after its whirlwind freshman year, one that saw ratings gradually climb until it became the No. 2 series on all of broadcast and revived hopes for prestige drama outside of cable and streaming, NBC will now see if This Is Us can continue its growth or, just as advantageously, retain the devoted audience it found last year. One particularly positive sign is the network 86-ing plans to move This Is Us to Thursday. It will remain on Tuesdays, starting Sept. 26, where it worked so well before.

And who's going to admit if anything is actually canceled?
Premiere Week used to come with its own guillotine. The most troubled series would get the ax after three or even two low-rated episodes — production shutdown, with the remaining footage never to see the pixilated light of day. But networks have become more and more reticent about bubble shows, often letting the poorest performers languish on the dial through November or December. Suddenly a mere 13 episodes was always the original plan. And while the writing is on the wall, the official word doesn't come until one anticlimactic May afternoon. Can anything pull such a poor linear performance this season that no one bothers waiting for the multiplatform numbers to roll in? We're about to find out.