The Achilles' heel of the top 5 Super Bowl contenders

Just because you're a Super Bowl contender, it doesn't mean you're flawless.

While the Dallas Cowboys only have one loss on the season, and teams like the New England Patriots and Seattle Seahawks have had their dominant stretches, 2016 lacks truly outstanding teams.

When the postseason rolls around, playoff teams are usually so close in quality that games often come down to one defining weakness.

Here are the Achilles' heels of the top five Super Bowl contenders:

Cowboys - Inability to force turnovers

The Cowboys have an embarrassment of riches on the offensive side of the ball. Dak Prescott, Ezekiel Elliott, and Dez Bryant are easily one of the best triplets in the league, and the likes of Cole Beasley and Jason Witten are the icing on the cake.

But on the other side of the ball, Dallas lacks few true difference-makers outside of Sean Lee, whose injury history means he could be lost at a moment's notice.

Dallas' bend-don't-break mentality has served them well this season. They're ranked third against the run and 21st against the pass, with the latter number likely inflated due to teams attempting comebacks against them.

In terms of forcing turnovers, though, they're one of the worst in the league. Only the Jaguars, Colts, Bears, and Jets have fewer takeaways - not exactly the company you want when gearing up for a playoff run.

The Cowboys have been saved by their offense's incredible protection of the football, turning the ball over only six times. But that's unlikely to be sustainable in the playoffs, especially with two rookies in the backfield.

Patriots - Lack of pass rush

Bill Belichick is a genius, and come playoff time he'll likely devise a defensive game plan that will make everyone who doubted him look foolish.

But at the moment, the Patriots look vulnerable on the defensive side of the ball, especially rushing the passer. New England's 22 team sacks are tied for 20th in the league, and the weakness will be more pronounced against playoff-caliber opponents.

If it wasn't for two timely turnovers, New England could have lost to Ryan Fitzpatrick, who torched the Pats Sunday for 269 yards and two touchdowns for a 115.2 passer rating. This is the same Ryan Fitzpatrick who's struggling to keep his job from Bryce Petty.

It's hard not to look at Chandler Jones and Jamie Collins - especially Jones, who has eight sacks for the Cardinals this season - and wonder if Belichick was right to give away his two biggest defensive playmakers.

Raiders - Big pass play vulnerability

The easy answer for the Raiders would be the defense as a whole, which looked horrendous early in the season. However, that narrative doesn't quiet hold up under closer scrutiny.

Yes, Oakland's defense is inferior to its high-flying offense. However, over the last four games the unit has shown considerable improvement, giving up an average of 317 yards and 20 points per game. Not spectacular, but more than good enough.

But the question is: Can they hold up against the best offenses the NFC has to offer? Oakland forced Cam Newton into a highly inefficient day, going 14-of-29, but he still finished with 246 yards passing - an average attempt of 8.5 yards.

Only the Titans and Browns have given up more plays of 20 yards or more than the Raiders, and those two teams have played one game more. Oakland's offense is as explosive as they come, and they'll need to continue to be if the defense can't do a better job of shutting down big plays.

Seahawks - Offensive line

If you're only as strong as your weakest link, then Seattle, for all its talent, will be undone by its offensive line come playoff time.

The Buccaneers' defense is far from good, especially their pass rush, but they dominated the Seahawks' cardboard cutout of an offensive line Sunday, sacking Russell Wilson six times and pressuring him on 50 percent of his dropbacks.

Wilson appears to be fully healthy, so he's now able to limit some of the pressure with his scrambling ability. However, he looked uncharacteristically off against the pressure versus Tampa Bay.

When Wilson is hot, the offensive line's struggles are manageable, as shown by the offense's 29.3 points per game average during the three-game winning streak prior to the Bucs game. But when he's average or worse, teams can feast on the porous offensive line. Seattle better hope it avoids any top edge-rushers in the postseason.

Chiefs - Alex Smith's passiveness

Every so often, Alex Smith reminds you of what he's capable of. In 2013, he went toe to toe with Andrew Luck in an epic playoff shootout, and on Sunday he brought the Chiefs back from the brink of defeat to take down the Broncos in overtime.

Unfortunately, these performances are few and far between. Smith is always more likely to be the passive, overly conservative passer that got the Chiefs down to the Broncos in the first place.

Kansas City ranks 28th in third-down efficiency, and most of the blame lays on Smith, who refuses to push the ball downfield, even when the down and distance dictates it. Only Sam Bradford has a lower average depth of target this season than his seven yards downfield, according to Pro Football Focus.

The Chiefs have all the pieces to make a playoff run, but will need to be perfect to compensate for Smith's flaws.