This week marks the unofficial start of the 2012-13 broadcast season with the season premiere of NBC’s The Voice tonight, followed by the debuts of new NBC comedies Go On, The New Normal and Guys With Kids and the season openers of NBC’s Parenthood, Fox’s The X Factor and ABC’s Shark Tank. More than ever this year, the Emmy Awards will not signal the kickoff of the new season. Of the five broadcast networks, only ABC — which carries the Emmys and will likely use it as a major promotional platform — and CBS — which has always stuck to a traditional rollout — will premiere the bulk of their fall lineups during premiere week, which starts on September 24.

It is not just the other networks’ desire to avoid the mayhem of premiere week that led to the most scattered fall launch I’ve ever seen — it started August 13 with the second-season premiere of NBC’s Grimm and ends November 2 with the debuts of ABC’s Last Man Standing and Malibu Country. Also factoring in is the fact this is an election year, so networks shifted some premiere dates to get longer runs uninterrupted by the four presidential/vice presidential debates on October 3, 11, 16 and 24 and Election Night on November 6. (ABC has been the most mindful of the disruptions, delaying the season premiere of Suburgatory until October 17 and the series debut of Nashville until October 10 so they only get one pre-emption each.) Additionally, NBC has been aggressive in trying to put on fall originals closer to its ratings record-breaking coverage of the London Olympics.

Somewhat surprisingly, this year there was only one minor scheduling change after the upfronts where most networks make their scheduling decisions in a vacuum, not knowing what the full competitive landscape would look like, leading to head-sratchers like the “comedy sigalert” at 9 PM on Tuesday when ABC, Fox and NBC all have quirky single-camera comedies. The one post-upfront change was ABC swapping Suburgatory and new alien family comedy The Neighbors in an effort to shore up freshman Nashville with a stronger lead-in from more the established Suburgatory.

But it is another last-minute scheduling move that made a lot of noise last week — NBC’s decision to add a third night to The Voice‘s premiere that will go head-to-head with the opening hour of Fox’s The X Factor, which will introduce new judge Britney Spears. (Coincidentally, both moves were orchestrated by the same scheduling executive, Jeff Bader, who moved from ABC to NBC last month.) The Voice‘s premiere expansion drew harsh criticism from X Factor creator Simon Cowell, who called it “cynical, cold-hearted, unprofessional”, “nothing short of dirty tricks” and claimed it broke a “gentleman’s agreement” with NBC to keep the two singing competitions on separate nights.

Ironically, the decision to add an extra Voice, Bader’s first major scheduling move at NBC, was made to give a stronger lead-in for the performance finale of Cowell’s NBC series America’s Got Talent. As for gentleman’s agreements, sources indicate that there may have been one that The X Factor won’t launch its new season in the same week as The Voice, something that didn’t happen.

Overall, NBC has the most at stake this fall after another lackluster season, which was propped up by the Super Bowl and a very strong Sunday Night Football to allow the network to lift off the ratings bottom for the first time in years, squeaking past ABC for third place in adults 18-49 for the season. The addition of a second, fall cycle of The Voice, is poised to tip the year-to-year comparisons in a positive direction. Still, the network is under enormous pressure to launch a new scripted hit, especially on the comedy side where its top performer, The Office, will end its run this coming season, along with awards darling 30 Rock. NBC started way before anyone else by previewing the full pilots for new comedies Go On and Animal Practice during its Olympics coverage. And the network is first out of the gate with regular half-hour comedy premieres this week, the only network to do so. But the lack of strong lead-ins besides The Voice and a puzzling schedule, with comedy blocks scattered on four nights and Thursday night left to fend for itself with aging comedies and the dismally-rated Rock Center as a 10 PM anchor, makes the network vulnerable.

Speaking of vulnerability, Fox’s fall schedule is like a shell game making viewers guess when their shows are on. The network faces the most pre-emptions this fall, with the four debates and Election night joining its already disruptive post-season baseball coverage. Fox has moved up the launch of 3 nights — Monday, Wednesday and Thursday — to early-mid-September in an effort to get longer stretches of uninterrupted originals after the detrimental effect a prolonged pre-emption had on breakout New Girl last fall. However, faced with the realities, the network doesn’t have many options but to solder on and hope that X Factor will stay at least even with its solid but lackluster first season, which didn’t have to compete with The Voice for viewers’ attention, and that its shows won’t suffer mightily from the forced hiatuses so early into the season. With CBS hosting the Super Bowl this season, Fox chairman Kevin Reilly already indicated that Fox may surrender the 18-49 season title for the first time in nine years.

For ABC, the biggest question this fall is whether an all-star edition of Dancing With The Stars would be able to stem the aging franchise’s steep ratings declines, hastened by its new time slot competitor, The Voice. Also worth keeping an eye on — will Shawn Ryan’s new submarine drama Last Resort become the first ABC scripted series since Ugly Betty to launch successfully in the “cursed” Thursday 8 PM slot or will it sink just like scores of other high-profile shows in the past four years?

With most of its lineup bulletproof, CBS will try to weather the storm of viewers sampling the slew of new series on the other networks before gravitating back to the tried-and-true menu of solid sitcoms and procedurals on CBS. It will be interesting to see how old new period mob drama Vegas starring Dennis Quaid would skew and whether Made In Jersey would become the first CBS series since CSI to successfully launch in the Friday 9 PM slot.

For the CW, the season will start later than ever as the network reversed its previous strategy of launching its lineup before the Big 4 to rolling it out in October, weeks after most new series on the other networks have premiered. After another miserable summer when the lights of the network stayed mainly off despite the biggest push with original programming in the network’s history, there was an encouraging sign on Friday when America’s Next Top Model posted its largest viewership since December.