Are the NFC’s Best Teams Set in Stone?

Last week, Dustin Baker of Vikings Territory suggested an interesting (if depressing) possibility: the NFC playoff teams have already been determined. After all, the Eagles, Lions, Bucs, 49ers, Rams, Packers, and Seahawks are off to strong starts, and it’s hard to imagine anyone knocking them out of the playoff picture.
He noted on social media, “One thing to start thinking about is that the NFC’s playoff crop may already be spoken for: Eagles, Lions, Packers, 49ers, Buccaneers, Rams, Seahawks? Like, do we really expect any of those teams, besides maybe Seattle, to fall from grace? Might have Commanders, Cardinals, Vikings, Falcons, Cowboys, etc. already fighting and clawing for a maybe-7th seed, with the hope SEA falls off. Feels quite early for the playoff picture to look pretty damn clear, but it feels like it is.”

But on the other hand, we’re still just 5 weeks into the season. There’s still plenty of time for teams to turn things around, for good or for ill.
To investigate this, I simulated a 17-game season with 32 teams (sorted from best to worst based on expected win probability) 10,000 times. I then studied how long it takes for the best teams to separate themselves from the pack. The correlation between expected and actual win percentage after a certain number of weeks for 10 simulated seasons is shown below:

It turns out, even 17 games are not enough. By the end of 17 games, the correlation coefficient r between skill and win percentage was just about 0.78, which essentially means that about 60% of a team’s final record is skill, and the remaining 40% is luck. In 29% of the simulations, at least one of the best five teams in the league finished with a losing record!
In real life, the NFC playoff teams perhaps feel more set in stone because the teams that are playing well are more or less the ones we expected to see in the playoffs at the beginning of the season.

But there’s still plenty of time for things to change; after all, the Packers and Vikings were projected to finish with roughly the same number of wins before the season, and at present they’re still neck and neck in the standings. Sam Darnold could turn into a pumpkin at any moment (as we know all too well from the end of the 2024 season), and a QB injury could knock an otherwise top-tier team off the pedestal.
There are clear favorites in the NFC playoff race right now, but for all of them to survive the season would be more surprising than not.