The Packers finished the regular season tied for first in the NFL in takeaways, while the Patriots ranked third. Despite giving up chunks of yards, Green Bay finished a mediocre but not disastrous 19th in points allowed, and the Patriots were 15th. Combined with dominant offenses, that's been good enough.
The Eagles offense, meanwhile, was hamstrung by turnovers, and the lack of takeaways was a missing element on defense.
The Eagles defense improved in most statistical categories this season. But they dipped in turnovers, generating 24 takeaways - tied for 17th in the league - after creating 34 a year ago, fifth-best.
Before that they had 38 takeaways in 2009 - second in the NFL - and 29, tied for eighth in 2008. The last time they failed to rate highly was in 2007, when their 19 takeaways were last in the NFL; the team finished 8-8.
It's easy to see the impact on the field. The Eagles' Week 1 visit to St. Louis was close until a Rams fumble led to a touchdown and sparked an Eagles blowout.
When the Eagles were embarrassed by the Patriots and Seahawks, they had no takeaways. In wins over the Dolphins and Jets they had seven, each one either giving the Eagles a short field or ending a drive that was within scoring range.
Turnovers change momentum, stop scoring drives, and create instant offense.
Of the last 10 Super Bowl participants, seven finished the regular season in the top 10 in takeaways; five were in the top five.
Turnovers were the biggest difference between the Saints' 8-8 2008 season and their 2009 championship. Their offense was strong and their defense near the bottom of the league in yards and points each year. But in 2009 they increased their takeaways from 22 to 39, and added eight in their postseason title run.
They sealed their title with an interception return for a touchdown.
Opportunism again fueled some of the top teams this season, helping suspect defenses find ways to aid powerful offenses.
"If we can get a chance to catch a ball or cause a fumble, we're trying to give it back to our offense as many times as we can," Packers safety Charlie Peprah recently told ESPN. "Just get the ball back to [quarterback Aaron Rodgers] and those guys as often and as much as possible."
Patriots nose tackle Vince Wilfork told the Boston Globe, "The more we can get [the offense] the ball, the better off we are as a team."
The same would seem to hold true in Philadelphia, where coach Andy Reid's team is built to score quickly and force opponents to play catch-up in the face of a fierce pass rush. He values takeaways.
Eagles practices routinely include drills to strip the ball. Reid first pursued Asante Samuel as a free agent because of the cornerback's penchant for interceptions, and it's no coincidence that Samuel's decline in picks coincided with the team's overall drop-off in takeaways.
Eagles players, asked about the issue during the season, struggled for concrete answers. Turnovers, they said, were just one of those things that sometimes happen and sometimes don't, and it was up to them to make plays when they had a chance.
(One theory here: the simplified pass rush, as effective as it was, was often predictable, perhaps sowing less confusion than a varied blitz scheme).
There are, of course, different ways to win. The Saints, with their powerful offense, were still a Super Bowl threat entering this weekend, despite ranking 31st in takeaways. The stout Broncos and Steelers defenses finished tied for 28th and 32d, respectively, in takeaways.
And under Steve Spagnuolo, the 2007 Giants finished tied for 21st in takeaways and still won a championship.
Defenses can be strong without creating turnovers.
But that hasn't been the Eagles' way. As Reid contemplates fixing his team's defensive mistakes, one focus will surely be forcing more errors by his opponents.
Contact staff writer Jonathan Tamari at 215-854-5214, firstname.lastname@example.org,
or @JonathanTamari on Twitter.