Of the last five Super Bowl winners, only the 2009 New Orleans Saints entered the playoffs as the No. 1 seed.
In most cases, wild-card teams like the 2010 Packers and 2007 Giants got hot near the end of the regular season, stormed into the playoffs and reeled off four wins en route to a Super Bowl Championship.
As the regular season comes to a close, the 2013 playoff picture is nearly all in place, save for the final wild-card spot in the NFC. The Atlanta Falcons already have the No. 1 seed and a playoff bye locked up in the NFC, while the Houston Texans will essentially play a must-win game against division rival Indianapolis to retain the top spot in the AFC.
While the Falcons have ridden their explosive offense to 65 points and victories over the Giants and Detroit Lions the past two weeks, the Texans appear vulnerable as they falter into the playoffs.
Both Houston, and to a lesser degree Atlanta, have flaws that could be exposed come playoff time by some of their lower-seeded conference foes.
Which No. 1 seed has the greatest chance at being upset in the playoffs?
Perhaps no team should be more familiar with that empty feeling than the Falcons themselves, who just two years ago ran into the offensive juggernaut that was Green Bay and were destroyed, 48-21, in the divisional round.
Turn the clock forward to 2013 and the result could be similarly disappointing for Matt Ryan and the high-flying Falcons.
This time, however, it's not Green Bay that presents the biggest threat to Atlanta's Super Bowl hopes, but the hottest team in the NFL—the Seattle Seahawks.
Pete Carroll has his team playing at another stratosphere right now, as Seattle's combination of hard-hitting, aggressive defense and innovative and explosive offense is unmatched. Over their last four games, the Seahawks have averaged 50 points, including a 42-13 blowout over the San Francisco 49ers on Sunday Night Football.
Rookie quarterback Russell Wilson and veteran running back Marshawn Lynch engineer an efficient offense that maximizes both players' talents. Wilson's extend plays with his feet and take shots with his cannon arm complement Lynch's patented "Beast Mode" running style.
The duo of Wilson & Lynch could present big matchup problems for a Falcons defense that's average at best this season. Atlanta ranks 23rd in pass defense and just 21st in run defense—numbers that don't bode well when matched up against a bruising back like Lynch.
Besides their problems against the run, Atlanta's inability to get after the quarterback could spell major trouble if matched up against Seattle. With just 29 sacks on the year—tied for 25th in the league—Atlanta struggles to move quarterbacks off their spot, which would be a necessity for a mobile quarterback like Wilson.
And while Atlanta's bread and butter is its fifth-ranked passing game, Matt Ryan, Roddy White and Julio Jones won't be cheery to run into Brandon Browner, Richard Sherman and the Seattle defense.
Often towering over opposing corners, White and Jones would actually be at a size disadvantage against Seattle's towering cornerback duo. Browner checks in at 6'4" and 221 pounds while Sherman—the league's best corner in 2012—is lean and mean at 6'3", 195 pounds.
Combined with a tenacious front seven that features rookies Bobby Wagner and Bruce Irvin to complement steady veterans like Chris Clemons and Red Bryant, Seattle is as complete a team as there is in the playoffs and the biggest threat to upset the Falcons.
Moving over to the AFC, the Houston Texans are stumbling into the playoffs and need a win against the Colts to hold onto their No. 1 seed.
While the Texans are lethal when they have a lead and can ride Arian Foster, they simply aren't built to come from behind because of their limited passing offense. Andre Johnson and Matt Schaub are a great pairing, but teams can double Johnson and not have to worry about many secondary threats.
No team exposed the Texans more than the New England Patriots on Monday Night Football just two weeks ago.
Considered the best team in the league, Houston entered the matchup confident and poised to take down the defending AFC champions, but left battered, bruised and on the wrong side of a 42-14 beating.
Assuming Houston still manages to keep hold of the No. 1 seed, New England is still the biggest threat to bouncing them from the playoffs.
Remember folks, the Patriots dropped 42 points on the Texans without Rob Gronkowski and with Logan Mankins and Chandler Jones making their way back from injuries.
With a much healthier lineup and a defense that's seen guys like Alfonzo Dennard, Dont'a Hightower and Devin McCourty emerge as consistent playmakers, the Patriots have the pieces to put an end to the Texans' Super Bowl hopes.
New England's balanced offensive attack can help negate the impact of J.J. Watt—who needs 2.5 sacks in the regular-season finale to break Michael Strahan's record of 22.5 sacks. Mixing in the run and play-action pass, along with firing some deep shots to Brandon Lloyd, can keep Houston's defense off balance.
Getting Gronk back would just be icing on the cake for the Pats and would only give Tom Brady another weapon in the passing game.
The Patriots aren't without their faults, but if their Week 14 win over the Texans holds any ground, Bill Belichick's team is the biggest threat to the AFC's probable No. 1 seed.