The mantra “defense wins championships” is a cliche in nearly every team sport, but when looking for common themes from this year’s NFL playoff participants, I discovered it may actually be true -- at least in regards to the 2015 NFL season.

I also learned some other interesting things.

For example, the Washington Redskins are an outlier in this year’s field, and four teams -- the Carolina Panthers, Seattle Seahawks, Arizona Cardinals and Pittsburgh Steelers -- have separated themselves as true all-around forces.

Using our signature nERD-based power rankings, ahead of five playoff teams.

With Alex Smith, Brian Hoyer, (a semblance of) Peyton Manning, A.J. McCarron and Teddy Bridgewater starting in the first weekend of the postseason, I guess it’s no surprise defense carried the day for a lot of the playoff teams.

I Take Offense to That

I’ll admit that I was surprised by the defensive trend. Maybe that’s the fantasy football nut in me -- you know, the guy who only cares about skill-position players.

But it’s not like we have a postseason full of Rex Grossman’s 2006 Chicago Bears. There are some great offenses, too, led by the Cardinals.

Arizona ended the regular season ranked first in Adjusted Offensive NEP per play. In fact, 9 of the 12 teams still playing football ranked in the top 12, with the Patriots (third), Steelers (fourth), Bengals (fifth), Seahawks (sixth) and Panthers (seventh) leading the way. Washington (9th), Minnesota (11th) and Green Bay (12th) also found a home in the top 12.

Kansas City ranked 14th, just missing the cutoff. The two glaring anomalies are Denver and Houston, who ranked 28th and 25th, respectively. The New Orleans Saints (2nd), Tampa Bay Buccaneers (8th) and New York Giants (10th) were exceptions the other way.

It didn't matter whether teams found offensive success on the ground or through the air. There were seven postseason teams apiece in both Adjusted Offensive Rushing NEP per play and Adjusted Offensive Passing NEP per play.

Each of the top five teams in per-play passing efficiency are still alive, with Arizona, Cincinnati, Seattle, Washington and New England (in order) locking down the first five slots. Pittsburgh (seventh) and Carolina (ninth) were the other two playoff teams inside the top 12.

Houston (27th), Denver (25th), Minnesota (20th), Kansas City (19th) and Green Bay (18th) -- yes, Aaron Rodgers' Packers -- are all still playing football despite ranking in the bottom half of the league.

Two of those teams -- the Vikings and Chiefs -- found major success on the ground. Kansas City ranked second in rushing efficiency while Minnesota was third. That’s especially impressive for Kansas City, considering Jamaal Charles carried the ball only 71 times this season.

Pittsburgh (4th), Carolina (5th), Seattle (6th), Arizona (8th) and New England (10th) also finished in the top 12 in Adjusted Offensive Rushing NEP per play.

Green Bay (15th) and Cincinnati (19th) had around average rushing attacks. On the other end of the spectrum, Houston (24th), Denver (27th) and Washington (28th) were among the league’s worst running teams. More on the Broncos' and Texans' offensive ineptitude in a second.

The Cream of the Crop

The Panthers, Cardinals, Steelers and Seahawks separated themselves as the premier all-around teams.

Each squad ranked in the top 10 in every per-play team metric -- Adjusted Offensive NEP per play, Adjusted Offensive Rushing NEP per play, Adjusted Offensive Passing NEP per play, Adjusted Defensive NEP per play, Adjusted Defensive Passing NEP per play and Adjusted Defensive Rushing NEP per play. To no one's surprise, those four teams sit atop our nERD power rankings.

Ironically, Seattle and Pittsburgh are both 6 seeds, which could make for some heavyweight clashes in the divisional round, if the Seahawks and Steelers can win on the road this weekend.

The Worst of the Best

Washington owes a lot of their success to Kirk Cousins. It’s not that the Redskins are terrible everywhere else -- they do rank 13th in Adjusted Defensive Rushing NEP per play -- but Adjusted Offensive Passing NEP per play is the only metric in which Washington falls in the top 10. In fact, the Redskins sit ninth in Adjusted Offensive NEP per play despite having one of the league’s worst rushing attacks (28th).

Denver and Houston are really interesting and similar teams. Each is phenomenal defensively -- the Broncos are first while the Texans are third -- but they’re two of the league’s least effective offenses. Houston checked in 25th while Denver finished 28th.