In the most recent Super Bowl, Carolina's unstoppable offense met Denver's immovable defense … and the Broncos won.
Rarely has there been a more resounding endorsement of defense, the brutal effectiveness of bookend pass rushes rounding the edge and applying vice-grip pressure to a quarterback.
That said, when seven teams switched coaches this offseason, each of them selected someone with offensive expertise. It's highly unusual for an entire crop of new coaches to come from the same side of the ball, but that's the case this season with Miami's Adam Gase, Cleveland's Hue Jackson, San Francisco's Chip Kelly, Tampa Bay's Dirk Koetter, Tennessee's Mike Mularkey, Philadelphia's Doug Pederson and the New York Giants' Ben McAdoo.
Six of those seven men have been NFL offensive coordinators, and the one who hasn't is Kelly, whose innovative offense at Oregon and then with the Philadelphia Eagles had a ripple effect throughout football.
Jackson made a point of not hiring an offensive coordinator when he got the top job in Cleveland. He did hire Pep Hamilton, who had that job in Indianapolis, but gave him the title of associate head coach —offense.
"Right now in my mind, I don't really plan on having an offensive coordinator," Jackson told Sirius XM NFL radio when he was hired. "Because I want to reserve the right to call plays. That's something that's gotten me this job, so it's something that you're an expert at. You want to continue to work at that and keep that in your pocket so you can use it to help your team."
Jackson will need to call on that creativity. Earlier this month he named as his starting quarterback Washington Redskins castoff Robert Griffin III, a player who last started in 2014 and didn't take a snap last season.
"We expect him to continue to ascend as he becomes more and more acclimated to the offensive system we will employ this season," Jackson said of Griffin, the No. 2 overall pick in 2012.
Koetter, who had been an NFL offensive coordinator since 2007, had that title in Tampa Bay last season and helped direct No. 1 pick Jameis Winston to one of the best seasons for a rookie quarterback in league history.
Regardless, the Buccaneers need the most help on defense. They ranked 26th in points allowed last season.
Likewise, McAdoo didn't switch teams and also was promoted from offensive coordinator, a position he held the past two seasons. He was hired to replace Tom Coughlin, who stepped down after 12 years as the team's head coach. The Giants are coming off a 6-10 season, the fourth year in a row they missed the playoffs.
By promoting McAdoo, the Giants maintained the continuity of the West Coast offense for Eli Manning.
"I guess from a selfish standpoint, yes, I'd like to be in the same offense," Manning said at the end of last season, before McAdoo was hired. "I think Coach McAdoo and I work well together, and our preparation and getting ready for each week. I think this year, I think I had a really firm grasp of the offense and what we were doing, we were on the same page, and I think we did a good job."
Mularkey isn't a newcomer in Tennessee; he coached the final nine games of 2015 after replacing the fired Ken Whisenhunt.
Gase was offensive coordinator in Chicago last season, and before had that job in Denver, where he worked closely with Peyton Manning.
Kelly was fired after nearly three seasons in Philadelphia (replaced with one game to go last season), and wound up on the opposite coast.