First, consider the Seahawks’ point differential. They allowed 407 points during the regular season while scoring just 310, meaning that they were outscored by roughly a touchdown per game on average. Although it is quite common for N.F.L. teams to reach the playoffs with a negative point differential, none has had one as poor as the Seahawks’ minus-97.

The Seahawks, moreover, were probably fortunate to be outscored by only 97 points. Measured by yardage, their offense ranked 28th of the 32 N.F.L. teams, while their defense ranked 27th. (Bizarrely, the San Diego Chargers led the N.F.L. in both categories, but finished 9-7 and missed the playoffs.) The Seahawks’ yardage differential — they were outgained by more than 1,100 yards this season, not counting special-teams plays — was the second-worst in football, ahead of only the Arizona Cardinals.

What’s more, the Seahawks compiled this inglorious record against mediocre opposition. Not only did they have the benefit of playing six games against the other weak teams in the N.F.C. West, but their four intra-conference games were scheduled against teams in the A.F.C. West, which was also rather weak this year. According to the ratings compiled by Jeff Sagarin of USA Today, the Seahawks’ schedule was the fifth easiest in the league.