If death and taxes are the two certainties of American life, the New England Patriots reaching the Super Bowl is the third.

When Bill Belichick and Tom Brady lead the Patriots out in Atlanta on Sunday, it will be their ninth appearance in the NFL showpiece of the past 17 years.

While a handful of other teams have recorded a similar tally of Super Bowl appearances, those achievements have spanned several decades.

No other franchise in NFL history comes close to matching the Patriots dynasty, which began with Brady and Belichick's upset of the then St. Louis Rams in 2002.

The achievement is made all the more remarkable by the fact that the NFL is specifically designed to make it hard for one team to dominate.

That is reflected by how few teams manage to reach back-to-back SuperBowls. The Patriots are one of only seven teams to repeat as NFL champions.

The league's salary cap, meanwhile, means that franchises can't simply bankroll their way to success.

Indeed, seven of the top nine highest-paid players in Sunday's Super Bowl will be turning out for the Los Angeles Rams.

So how have the Patriots managed to buck the trend for so long?

Well, being able to draw on the greatest quarterback and greatest coach in NFL history for so long is the cornerstone.

"We've been privileged to keep continuity with two people who are unbelievable at what they do," said Patriots owner Robert Kraft this week.

"It's almost two decades we've been able to keep this thing running together."

Kurt Warner, the St. Louis Rams quarterback who faced Brady back in the 2002 Super Bowl, agreed.

"I think it all starts with Bill and Tom," Warner said. "Those are two great pieces to build around."

Bargain players

Warner believes Belichick's signature genius however has been in managing to consistently identify players who will fit seamlessly into the Patriots set-up to perform a specific task.

Often, Belichick recruits players who have been overlooked by the rest of the league. Sixteen members of the Patriots 53-man Super Bowl roster were signed as undrafted free agents.

That list includes fullback James Develin, a crucial part of the Patriots running game who arrived in the NFL after stints with the Arena Football League's Oklahoma City Dawgz and Florida Tuskers of the now-defunct United Football League.

Similarly, center David Andrews, signed as a rookie free agent in 2015, has emerged as one of the best offensive linemen in the NFL.

"I think the Patriots have been as good as anybody about not necessarily acquiring the best talent, but acquiring the best players for what they need them to do," Warner said.

"They might not be Hall of Fame players, but when you put them in the Patriots system they play at Hall of Fame levels."

Finding champagne players for beer prices also has obvious implications for the payroll.

"They haven't had to pay these huge enormous contracts," Warner said. "They've done it through good scouting and identifying players who can fit their scheme."

Meanwhile, Eric Decker, who retired from the NFL last August after training with the Patriots during the off-season, said the team's fabled "Patriot Way" locker room ethos was another factor.

"They're great for a reason," Decker said. "The Patriot Way is real, and it starts at the top. They've got a great owner, a great head coach, and Tom Brady.

"In the locker room, everyone loves each other, knows what their role is, works hard, keeps their mouth shut.

"So they are conditioned in a way, mentally and physically, to outlast people. And that's how they end up in the big game."