According to the NFL, teams that win on opening day have a 52% chance of making the playoffs.
Teams that lose on opening day, have just a 24% chance. That’s quite a difference on just one single game/win.
Here’s the NFL’s numbers:
Since 2002, when the NFL expanded to 32 clubs, teams that are victorious in their season-openers are more than twice as likely to reach the playoffs than those that lose an opening game.
Of the 319 teams that won openers…166 went to the playoffs (112 won division titles).
Of the 317 teams that lost openers…78 went to the playoffs (48 won division titles).
Note: There are a different number of winning and losing teams in season-opening games due to the inclusion of 2017 Week 2 victories by Miami and Tampa Bay, which was the season-opener for each team (their Week 1 meeting was postponed due to Hurricane Irma).
In 2021, the 14 playoff teams compiled a 9-5 record on Kickoff Weekend.