In 2010, the Patriots, the Steelers, the Ravens, the Colts and the Chiefs made the playoffs, a situation that could repeat this year.

In 2009, it was the Patriots, the Colts, the Bengals, the Ravens and the Chargers in the playoffs, which we might see again.

The story of the A.F.C. begins with its two future Hall of Fame quarterbacks, Tom Brady and Peyton Manning. The last year any A.F.C. East team finished with a better record than the Patriots was, incredibly, 2000. Since then, New England has won the division title every year except 2002 and 2008, when the team lost tiebreakers to the Jets and the Miami Dolphins. New England, with Brady’s help, has won at least 10 games in a remarkable 12 consecutive seasons, a mark matched only by the San Francisco 49ers (from 1983 to 1998).

Perhaps there should be an asterisk next to that milestone because teams quarterbacked by Manning — the 2002 through 2010 Colts and the 2012 through 2014 Broncos — have also won at least 10 games in 12 straight years. (Manning missed the 2011 season because of neck injuries.) Each of the last 11 A.F.C. championship games has featured the Patriots, Manning or the Steelers.

After Brady’s and Manning’s squads, Pittsburgh and Baltimore have been the next most dominant teams in the conference over the last 15 years. The two have made nine appearances in A.F.C. title games since 2000.

The hierarchy changes at a glacial pace in the conference, but over the last four years, the Bengals — at 39-22-1 — have the third-best record in the A.F.C., after the Patriots and the Broncos. Cincinnati is on a pace to make the playoffs for a fourth straight season and is now becoming a part of the conference’s elite.

As remarkable as the success of the top teams in the conference has been, the struggles of teams like the Raiders, the Jaguars, the Jets and the Titans have been as consistent. Over the last three years, those teams have been outscored by at least 100 more points than every other team in the N.F.L.