New Orleans Saints wide receiver Keith Kirkwood (18) celebrates a touchdown with New Orleans Saints wide receiver Michael Thomas (13) agains the Philadelphia Eagles in the first half of the divisional round of the NFC playoff game in New Orleans, Sunday, Jan. 13, 2019.

Super Bowl 48 was supposed to settle the debate.

The Denver Broncos had the most productive offense in NFL history, one that put up an eye-popping 37.9 points per game. The Seattle Seahawks had a defense that allowed 14.4 points during the 2013 regular season.

The football world was ready to find the answer to that age-old adage: Does defense really win championships?

Five years later, the discussion continues.

“We called the game, and Denver was the No. 1 scoring offense, and they were playing the Seattle defense, and Seattle ran them out of the stadium by halftime,” said Fox football broadcaster Troy Aikman, who called the game with colleague Joe Buck. “They totally shut that offense down. Now, I’m not willing to say great offenses always prevail, but it has this year.”

The few seasons before that game, and in the years to follow, a trend was building in the NFL: The most successful teams continued to score more points on offense and surrender more on defense. That trend exploded this season across the upper echelon of the league.

For the first time since at least 1991, the NFL’s top four scoring offenses all qualified for the conference championship games, which unfold Sunday. Together, they combine for the highest average points per game in the regular season between conference championship teams (31.73) — nearly eight points higher than the Ravens, Raiders, Giants and Vikings did in 2000.

In nine seasons from 2000-12, only one of the league’s most productive four offenses reached the conference championships. Meanwhile, in three of the past four years, at least three of the best four scoring offenses have reached this point.

As for the defense ...

Of the four squads still alive, the Patriots have the stingiest defense, giving up the seventh-fewest points in the league, with the Saints (14th), the Rams (20th) and the Chiefs (24th) trailing. This weekend represents the first time since 2000 that none of the league’s top four defenses landed in the championship round.

The Saints, Rams, Patriots and Chiefs have combined to give up the most points (23.18) of any of the last four teams standing since at least 2000 — a trend that has been heading in this direction since at least 2000, when the final four teams gave up an average of 16.9 points per game.

Only time will tell just how much an anomaly NFL fans will be watching this Sunday, and the reasoning for the stats are still somewhat unclear, but they’re certainly hard to ignore.

“It’s not just about having the best defense anymore, but the best offense, too,” Saints receiver Ted Ginn Jr. said. “It shows you how the game is evolving and how the coaching is evolving and where the movement of the league is going.”

Some of it could be explained by those at NFL headquarters. Along with working to reduce head injuries in recent years, Aikman said he believes the NFL has made a conscious effort to increase scoring with rules an penalties. It’s a trend that has carried over to the NBA and Major League Baseball, too.

“Those rule changes, they protect the receivers a little more and the quarterback, and it opens up some routes that may not have been open before,” Saints fullback Zach Line said.

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And with those new rules, the brightest minds in the game will almost always be the first ones to best learn how to exploit them. When you look over the offensive team rankings over the last decade, Sean Payton’s Saints, Bill Belichick’s Patriots and Andy Reid’s Eagles and Chiefs have consistently risen toward the top of the league, as offenses have shifted to featuring the passing game.

“I’ve seen over the last few years when some of these rules maybe weren’t taken advantage of, but now they are,” Saints defensive coordinator Dennis Allen said. “Now you can have an offensive player come and block a player that’s covering somebody within a yard of the line (of scrimmage), and that’s totally legal.

“And I think the better coaches know what the rules are and try to take advantage of those rules when they can.”

You even see that offense-first trend in teams who struggled the most this season. Of the eight front offices who fired their head coaches, six have hired or plan to hire a coach who was heavily involved in the offense at his most recent stop.

The joke around the NFL that anyone who had shared a cup of coffee with McVay could run an NFL offense wasn’t that far off.

Eventually, the game may reach a tipping point, shifting its focus toward defense.

Ginn Jr. said he saw a bit of that around 2010, when the Steelers, Jets, Packers and Bears made it to the conference championships with four of the league’s top six defenses.

“You started seeing a lot of guys coming in that were really fast at the defensive end, and that started to change the game where you went from offensive tackles being 320 (pounds) to 285 or 290,” he said. “I’ve seen a lot of that happen in my time.”

Even before that shift-to-defense trend returns, the Saints locker room stands by the old notion that defense wins championships. But with the league’s strongest four offenses facing off Sunday, defense may in fact be the deciding factor.

“There’s no offense that can win a championship alone,” Saints left tackle Terron Armstead said.

Payton agreed.

“Generally when the season is over with, the best team wins,” he said. “And that’s not just in one area.”

Follow Nathan Brown on Twitter, @nbrownadvocate.