The NFL's 55th Super Bowl on Sunday will be celebrated in some corners as a victory for the game's old hands — Tampa Bay's Bruce Arians and Kansas City's Andy Reid, coaches in their 60s who ousted coaches in their 40s in the last round. But the matchup in Tampa on Sunday is a testament to the ways two of the game's oldest coaches have adapted to some of its newest trends.

Reid's decision to merge his West Coast offense roots with some of the Air Raid concepts Patrick Mahomes ran at Texas Tech is well-documented. The Kansas City coach has built his second act around heavy use of motion and play-action, one of the league's most aggressive pass-run ratios and a bold approach to fourth downs.

Arians' "no risk it, no biscuit" catchphrase has long underscored his preference for downfield passing concepts, but the Buccaneers shifted their scheme later in the season to incorporate more motion, while achieving impressive results when they called play-action passes for Tom Brady.

Mahomes will try to become the league's youngest quarterback to win back-to-back Super Bowls on Sunday. Brady, at age 43, will play in his 10th Super Bowl and try to add to his already incomparable résumé. Their sexagenarian coaches, when met with quarterbacking greatness, have catered to it.

"[Tom and I] were just talking about, back in the day, if you had 26 attempts and 204 yards, that was a huge day most Sundays," said Buccaneers offensive coordinator Byron Leftwich, who spent 10 seasons in the NFL as a quarterback for four teams. "This is an aggressive league. This isn't the same league where you ran the ball and got 2 yards on first down. [Arians'] slogan fits perfectly for the way football is being played now."

Passing fancy

Kansas City and Tampa Bay's commitment to the quarterbacks begins in the simplest way possible: the frequency with which they put the game in those players' hands.

According to data from NFL Fast R, the Chiefs had the highest rate in the league by throwing 64.7% of the time in neutral situations (defined as when both teams still have at least a 20% win probability). Tampa Bay was fourth at 56.2%.

The Chiefs threw more often than expected in all situations but third-and-short; the Buccaneers threw less than expected on first downs but more than expected in all other situations. The two teams they beat in the conference championship games (Green Bay and Buffalo) were third and seventh in neutral-situation pass frequency, respectively.

(The Vikings, by way of contrast, were 26th in neutral-situation pass frequency at 48.7%, and ran more than expected in all situations other than second-and-3-to-7 yards and after running for a first down.)

According to Football Outsiders, the Chiefs threw 72% of the time in the first half, the highest rate in the league. It didn't stop them from making heavy use of play-action to get linebackers to bite and open up throwing windows. Pro Football Focus charted Mahomes as throwing off play-action 30.8% of the time, the seventh-highest percentage in the league. Brady's play-action percentage ticked up from 18% before the Buccaneers' bye week to 25% after it; his 134.0 passer rating off play-action was the league's best in that time.

"Kansas City has the best quarterback in the game, so they really don't care about some kind of run balance," said Football Outsiders founder Aaron Schatz. "They know as long as you run it a couple times, you sort of established the run. The way I put it is, the run has been established by 100 years of NFL history. It's already been established that teams can hand off, so you can start running play-action right from the get-go."

Use of presnap motion

Embracing another growing NFL trend — presnap motion — helped Arians, Leftwich and Brady turn around the Buccaneers offense midseason.

More NFL offenses are shifting players before the snap, which can help quarterbacks identify coverages, distract defenders or kick-start the running game. About 46% of plays this season included some form of presnap motion, according to ESPN, a rate that has risen annually from 33% in 2017.

This year, all eight divisional-round playoff teams, including Kevin Stefanski's Browns, had higher motion rates than the Vikings' 40%, which ranked 20th in the league.

Arians has questioned the merits of motion, in part, because one of his former quarterbacks, Peyton Manning, was opposed it. But among the Bucs' biggest changes since limping into the bye week at 7-5 has been more presnap motion — about 56% of their plays, according to Sports Info Solutions. Brady has been more effective, averaging 3 more yards per throw than without motion.

"September, we just scratched out a game or two, really had no clue what we were doing," Arians said. "October got a little bit better and after the bye week, I think things started to click and everybody got comfortable with each other."

Reid's Chiefs have become synonymous with a motion offense. Only the 49ers and Ravens leaned more on presnap movement than Kansas City's 59%, which was especially effective creating space near the goal line. Nobody had more red-zone rushing touchdowns with motion than the Chiefs, per ESPN. There's otherwise little reason to fear Kansas City's rushing attack. But Reid and coordinator Eric Bieniemy continually bait defenses into looking the wrong way.

"They're near the top of the league in both play-action and motion," Schatz said. "Those are things that both analytics people and film study people agree lead to a more dynamic offense."

Fourth-down strategy

The Chiefs and Bucs differ most on fourth down. Where Reid's foot is almost always on the gas — Kansas City is the NFL's fifth-most aggressive, going for it nearly 60% of situations recommended by the New York Times' 4th Down Bot — Arians' "risk-it" philosophy stops. He often switches out Brady for Tampa Bay's vaunted defense on fourth downs; the Bucs rank 31st in going for it when data suggest they should.

Even when the Chiefs, without Mahomes because of a concussion, clung to a 22-17 lead over the Browns in the AFC divisional round, Reid had backup quarterback Chad Henne seal the win on a fourth-and-inches play with a quick pass to Tyreek Hill.

"That's why we love Big Red," Chiefs safety Tyrann Mathieu told reporters after the game. "[Reid] is always on time. He's like our spirit warrior out here, you know, behind the scenes. He's always firing us up. We always know he's got one play in the chamber."

Tendencies can be broken. Arians considered the Chiefs' firepower during their first meeting on Nov. 29. Trailing 17 points with 13 minutes remaining, the Bucs threw a counterpunch. Despite being in field goal range on fourth-and-short, Brady uncorked a 31-yard touchdown to receiver Mike Evans. Brady led another touchdown drive, but Tampa Bay's offense didn't get the ball back in the 27-24 loss to Kansas City.

"We can hit every throw," Brady told reporters after the game. "We're going to keep taking them."