Houston (AFP) - With four Super Bowl wins in a career which has spanned 16 seasons, Tom Brady has already earned the right to be regarded as one of the quarterback greats.
Will one more on Sunday make him the greatest? It's a subjective question, the answer depending on your definition.
One more win on Sunday will take him clear of his boyhood idol Joe Montana and Pittsburgh Steelers great Terry Bradshaw, who also have four Super Bowl rings.
"I think if Tom wins this game, and I never thought I'd say this, he surpasses Joe Montana as the greatest ever," said Green Bay Packers legend Brett Favre.
"Right now, in my opinion he and Joe Montana are a dead heat."
Others say Brady is already firmly into Greatest Of All Time territory, irrespective of Sunday's result.
- The greatest -
"I see the greatest quarterback that's ever played the game of professional football," said former Washington Redskins quarterback Joe Theismann. "And I don't think he needs to win this Super Bowl to be considered that," Theismann added.
The Baltimore Ravens' two-time Super Bowl winner Ray Lewis agreed.
"People can hate on him, y'all can be mad at him, but he's the best quarterback we've ever seen," Lewis said.
Brady himself has declined invitations to join the debate on his place in the quarterback pantheon.
"I don't think anything about, you know, 'personal legacy,'" Brady told reporters.
"Those words never even come out of my mouth unless I've repeated them. Those things have never been important to me."
Brady instead has maintained a singular focus on the job in hand as he aims to crown a season which began with a four-game suspension following the Deflategate saga with the sweetest revenge of all.
Brady's simmering feud with National Football League commissioner Roger Goodell over the affair has provided the most alluring sub-plot of this year's Super Bowl.
Publicly, Brady insists he has put Deflategate behind him, maintaining that loyalty to his team-mates -- rather than exacting revenge on Goodell -- is his priority.
"This is my motivation -- these fellows right in front of me," Brady said after the Patriots destroyed the Pittsburgh Steelers to seal their place in the Super Bowl two weeks ago. "We'll see if we can write the perfect ending."
- Relentless drive -
Yet given the quarterback's drive, it is hard to imagine he has simply "moved on" from the scandal, as he told reporters following his return from suspension last October.
This is, after all, an individual who has built a career out of a determination to prove others wrong, often successfully.
At the University of Michigan, he once threatened to transfer colleges, in frustration at not getting game time, before deciding to stay.
"From that day forward, he was relentless in the pursuit of proving who he was," Michigan's head coach at the time, Lloyd Carr, said in a 2015 interview.
The story of Brady's rise through the ranks at the Patriots has become the stuff of NFL folklore.
Arriving after being chosen with the 199th pick in the sixth round of the 2000 draft, the gangly kid started out as fourth choice in the quarterback pecking order.
But his ferocious work ethic rapidly marked him out. Team officials would get calls late at night to inform them that Brady had arrived at the team's training facility, to practice by himself.
By the time that incumbent quarterback Drew Bledsoe was injured at the start of the 2001 season, Brady had worked his way up to understudy.
When his chance came, following a serious injury to Bledsoe in September 2001, he was ready.
Brady assumed the starter's jersey and held onto it that season.
The following February, Brady led the Patriots to an upset 20-17 Super Bowl win over the St. Louis Rams, producing an ice-cool final drive to set up the game-winning field goal.
That nerveless display was to become Brady's calling card over the next decade-and-a-half, which yielded three more Super Bowl rings, two losing Super Bowl appearances, and finally, another tilt at glory on Sunday.
Theismann believes Brady's ability to thrive at the hub of vastly different Patriots teams is what sets him apart as the greatest.
"If you look at everybody on the New England Patriots that have played with Tom Brady, it's almost like a turnstile," said Theismann.
"Guys come, guys go. Everything changes. Except one thing - Tom."