Aaron Rodgers leads one of a trio of potent offenses — backed by suspect defenses — into the postseason. (Bill Kostroun/AP)

Good defense was a scarce commodity during an NFL regular season in which Drew Brees, Aaron Rodgers, Tom Brady and other quarterbacks carved up opposing secondaries with record-setting passing proficiency.

But now that the playoffs have arrived, do teams such as Brees’s New Orleans Saints, Rodgers’s Green Bay Packers or Brady’s New England Patriots have to play much better defense to win a Super Bowl title?

With the sport’s new passing-crazed style of play challenging the traditional notion that a stalwart defense is a fundamental ingredient for postseason success, these playoffs will provide an intriguing look at the way to win in the NFL when the stakes are highest.

“If you want to just make it a full-on seven-on-seven [passing-drill] league, then the Super Bowl will look like Baylor and Washington,” said former San Francisco 49ers offensive lineman Randy Cross, referring to the recent Alamo Bowl, which Baylor won, 67-56. “They really have legislated defense almost out of the game, at least the physical intimidation side of it. They say that isn’t true. But you can’t tell me that receivers don’t feel a little more comfortable going over the middle than they used to feel.”

The Saints, Patriots and Packers were the league’s top three teams in both total offense and scoring offense. But defense was another matter entirely. The Saints ranked 24th among the 32 NFL teams in total defense (based on yards allowed) during the regular season. The Patriots were 31st and the Packers were last.

Their formula worked exceedingly well during the regular season. The Packers and the Patriots are the top seeds in the NFC and AFC, respectively, and have first-round playoff byes. The Saints are the NFC’s third seed and enter the postseason on an eight-game winning streak.

But some experts are skeptical that a team can thrive in the postseason playing that way. Of the 45 teams to win Super Bowl titles, 38 had a top-10 defense.

“If the defenses aren’t real good, I think there’s some vulnerability there,” said former Buffalo Bills coach Marv Levy.

Defensive statistics for the Packers, Patriots and Saints might have been skewed, Levy noted, by opponents sometimes piling up meaningless passing yards as they faced big deficits late in games.

But he also believes that “if you gave me my choice, I’d want a great defense first. I once made a comment that offense sells tickets, kicking wins games and defense wins championships. I think that still holds true, to me. That’s no disrespect to all these great quarterbacks and what they’ve done. [But] I have a little apprehension about a team that is vulnerable on defense, no matter how potent their offense is.”

The three offensive juggernauts fared better in the category of scoring defense. The Saints ranked 13th in the league, the Patriots were 15th and the Packers were 19th. The Packers and Patriots also had two of the league’s top turnover margins, plus-24 for Green Bay and plus-17 for New England. Still, Cross said he, too, had concerns.

“They say, ‘We’re going to get turnovers. We’re going to give up field goals. We won’t worry about the yards.’ . . . [But] there’s a reason that teams like that have traditionally struggled in the postseason,” Cross said.

“What if the Patriots get down 21-0 to Pittsburgh or Baltimore? What if Green Bay or New Orleans gets down 21-0 to San Francisco? You’re going to tell me that you’re just going to come spinning right back into the game if you get down 21-0 to a team like that? Things change in the postseason. People play a little differently. The panic goes way up if you get behind.”

Former NFL coach Dan Reeves said he has become convinced it’s possible in today’s NFL for a team with major defensive flaws to win the Super Bowl. He recalled watching the Indianapolis Colts surrender 375 rushing yards to the Jacksonville Jaguars in a December game in 2006, before they went on to win the Super Bowl. Those Colts ranked last in rushing defense and 21st in total defense.

“I said, ‘There’s no way they can win the Super Bowl,’ but I was wrong,” Reeves said. “They did play some better defense in the playoffs. But the last several years, we’ve seen it go this way. It’s not who plays great defense and runs the ball any more. That’s the old-school way. If it was about that, you could give the trophy to San Francisco right now.”

He expects more of the same in the postseason.

“If it’s an indoor game or it’s outside with good weather, you won’t see anything different,” Reeves said. “If it’s windy or snowy, you might see more emphasis on the running game. But for the most part, those teams won’t change anything. You have exceptional quarterback play and offenses.”

The Saints ranked 25th in total defense when they won the Super Bowl after the 2009 season. But in other recent seasons, Super Bowl triumphs have been achieved with a more traditional approach. The Steelers ranked first in the league in total defense in the 2008 season on their way to a Super Bowl victory. Last season’s Packers had Rodgers, but they also ranked fifth in the league in total defense.

This season’s playoff field includes the league’s four highest-ranked defenses. Pittsburgh led the league in total defense while Houston ranked second, Baltimore was third and San Francisco was fourth.

Nevertheless, this season almost certainly will be remembered as the greatest passing season in league history. Brees set single-season NFL records for passing yards, with 5,476, and completion percentage, at 71.2 percent. Brady and Detroit’s Matthew Stafford joined Brees in surpassing 5,000 passing yards. Before this season, there had been only two 5,000-yard passing seasons in league history, by Dan Marino for the Miami Dolphins in 1984 and by Brees for the Saints in 2008.

Rodgers might have joined Brees, Brady and Stafford in the 5,000-yard club if he hadn’t sat out the Packers’ regular season finale with the top seed in the NFC playoffs already secured. His backup, Matt Flynn, took over and threw for 480 yards and six touchdowns against the Lions in a passing duel in which Stafford threw for 520 yards and five touchdowns.

Rodgers’s passer rating of 122.5 this season was the highest ever. League wide, teams set single-season records for net passing yards (passing yards minus yards lost on sacks), passer rating and total points, according to the NFL.

The Packers, Patriots and Saints had a combined regular season record of 41-7 and gave the NFL three teams with more than 500 points scored in the same season for the first time ever.

“It is a passing league,” former Buffalo Bills safety Mark Kelso said. “If Green Bay and New Orleans play in the [NFC] championship game, I know I’ll be watching. I mean, they [the Packers] have a backup quarterback who can throw for over 450 yards and six touchdowns.”

Yet Kelso cited the Patriots, with their powerful offense led by Brady and wide receiver Randy Moss, losing their unbeaten season with a Super Bowl defeat against the New York Giants to end the 2007 season.

“When New England was close to the perfect season, it was the Giants’ defense and pressure with the pass rush that was largely responsible for winning that game, along with some plays on offense at the end,” Kelso said. “We still might see scores in the upper 20s or in the 30s this year in the playoffs. But I think ultimately it will be the team that slows down one of those offenses that wins.”

More NFL playoffs coverage from Washington Post Sports:

Wild Card previews: Falcons-Giants | Steelers-Broncos | Bengals-Texans | Lions-Saints

Patriots, Saints ride long winning streaks into postseason

Early Lead: John Elway tells Tim Tebow to ‘just pull the trigger’

Early Lead: Pittsburgh’s Ryan Clark won’t play in Denver due to sickle cell trait

Playoff scoreboard: Schedule and results