Going unbeaten shouldn t be that hard these days, logic would dictate. Schedules are uneven, with some divisions noticeably weaker than others. Teams can make a huge improvement from one season to another with a few shrewd free agency signings. Pick up a fifth place schedule, bring in some new talent via the draft or free agency and hey presto, you ve got yourself an unbeaten season. The modern NFL doesn t work like that.
More teams are in contention for play-off spots at season s end, so there are fewer easy games.
There are 16 games in a season nowadays. The game is a lot more physical, with bigger and faster players than back in the 70 s, hence more injuries. Eventually, even the best teams find one game just too tough. One day, another team will achieve an unbeaten season. Until then, the Miami Dolphins of 1972 will have the honor of being the only team to go unbeaten in a NFL season.