There was an old-school appeal to this system, but it had a lot of problems. Teams that had great seasons were shut out, and the playoffs were a brutally short affair.
With the 1970 AFL/NFL merger, there were suddenly two conferences with three divisions each. With an odd number of playoff teams within each conference, something had to be done.
Introducing: The Wild Card
To even out the brackets, the NFL added the winningest non-division-winning team from each conference. These two teams soon came to be known as the "wild cards."
It didn't take long for the NFL to realize the potential of this format. Having more teams in the playoffs made the regular season more interesting. More playoff games meant more tickets to sell and more of the league's most compelling games on TV.
In 1978, the NFL expanded the regular season to its current 16 games; the playoffs expanded with it. Each conference now had two wild-card berths, and a week was added to the postseason schedule to accommodate an initial Wild Card Round.
In 1990, the NFL added a third wild-card berth to each conference, ensuring a total of 12 teams in the NFL postseason.
Finally, when the league expanded to 32 teams in 2002, realignment yielded four divisions per conference, allowing the league to invite all four division winners to the postseason, give byes to the top two seeds and reduce the number of wild cards from six back down to four.
A Big Mountain To Climb
With the 2002 realignment, the top two seeds got byes into the second round, and the bottom two division winners would face the wild cards in the first. In the second round, the top remaining seeds face the bottom remaining seeds, giving the top division champs another big advantage.
Finally, home-field advantage goes to the top seed in any given game. So, to win the Super Bowl, the fifth- and sixth-seed wild cards will almost certainly have to win three straight playoff games on the road. It's no wonder so few have done it.
This is a timeline of all 10 wild-card teams to make the Super Bowl; six have won it.
In the first eight years of the single wild card, only one team made it to the Super Bowl. In the 12 years following that, with two wild-card berths per conference, two teams made it to the Super Bowl, including the first wild-card winner: the 1980 Oakland Raiders.
So 20 years of four-team playoffs only saw one winner of the three wild cards to make it to the big game. In the 23 years of six-team playoffs since, six wild cards made the Super Bowl, and five won it.
Counting just from the 2002 realignment to 2011, the NFL has seen three Super Bowl champions in nine years. What should almost never happen is suddenly happening almost as often as not.
What's going on?
A Common Profile
Both the 2005 Pittsburgh Steelers and 2010 Green Bay Packers had incredibly stingy defenses. The Steelers allowed an average of 16.1 points per game, third-best in the NFL. The Packers were even harder to score on; their second-best scoring defense allowed just 15.0 points per game.
The 2007 New York Giants defense wasn't so hot over the course of the regular season, but during the playoffs they were more than up to the task. Over the course of three playoff games and the Super Bowl, they allowed just 16.25 points.
A big part of scoring defense, of course, is a fierce pass rush. Those Giants out-sacked opponents 52-28 over the course of the year. That Packers squad out-sacked their opponents 47-38. The Steelers? Their defense sacked the opposing quarterback 47 times, while their offense allowed only 32 sacks.
Finally, the common thread that ties all three teams? A quarterback who takes care of the ball.
During the four games of the 2005 playoffs, Roethlisberger threw seven touchdowns and three interceptions. During the 2007 playoffs, Manning threw six touchdowns to just one pick. In 2010, Aaron Rodgers threw nine touchdowns and only two picks.
Who Fits the Mold?
The Minnesota Vikings, Seattle Seahawks, Indianapolis Colts and Cincinnati Bengals all hope they can keep the trend of wild-card champions going. But which teams fit the mold of the recent upset kings?
Well, not the Colts. Their scoring defense is in the bottom half of the NFL, quarterback Andrew Luck has a 23-to-18 touchdown-to-interception ratio, and he's been sacked nine more times (41) than his defense has managed to sack (32).
The Vikings defense isn't especially stingy (21.8 average points per game allowed), but they do get after the quarterback (44 sacks against 32 allowed). Christian Ponder has thrown more touchdowns (18) than interceptions (12), but not many.
The Bengals could make a run; they boast the eighth-best scoring defense in the NFL (20.0 points per game), as well as a quarterback who's thrown almost twice as many touchdowns (27) as interceptions (16). Their defense gets after the quarterback, having notched 50 sacks on the season, but they've also allowed 46. They'll need better pass protection in the playoffs if they want to make it to the mountain top.
Then, we have the Seahawks.
The Seahawks have the No. 1 scoring defense in the NFL this season, allowing just 15.3 points per game. They're out-sacking opponents 36 to 33, and quarterback Russell Wilson boasts an outstanding 26 touchdown passes to just 10 interceptions.
If there's any team that can make a run from the wild-card basement to the top of the podium this year, it's the Seahawks.