PHOENIX - They're like X and O, tuck and rule, hood- and -ie, super and model, and spy and deflate.
You can't have Tom Brady without Bill Belichick, and you can't have the coach without the quarterback.
Their legacies are intertwined, win or lose, good or bad, and whatever happens for the New England Patriots in Super Bowl XLIX on Sunday against the Seattle Seahawks, Brady and Belichick will likely get either most of the credit or most of the blame.
Brady and Belichick have already accomplished more than almost any other pairing in the Super Bowl era. They've won three titles together - matching Joe Montana and Bill Walsh with the 49ers - and only Terry Bradshaw and Chuck Noll of the Steelers combined for four.
Brady and Belichick have already gone to more Super Bowls than any other tandem and will expand that number to six on Sunday. If they claim a fourth Vince Lombardi Trophy, they will etch their names as the most proficient duo in modern football. Only the Lombardi-Bart Starr Packers of the pre-Super Bowl NFL would have won more titles (five) together.
But if they lose, it will be for the third straight time, since beating the Eagles by 24-21 10 years ago at Super Bowl XXXIX. Brady and Belichick are already individually considered among the best ever, but would another runner-up finish tarnish their legacy?
"In my mind, it wouldn't change it a whole lot," said Cris Collinsworth, who will broadcast Sunday's game on NBC. "I've already got them in that category, as two of the greatest of all-time. I think they're both Hall of Famers. . . .
"There's no discussion to be had. Those two guys are already in that category."
Brady, 37, has won an amazing 77 percent of his starts (160-47 record) after sitting most of his rookie season. In his 15-year career, he has thrown for 53,258 yards and 392 touchdowns, and is arguably as good now as he was 10 years ago.
The 62-year-old Belichick, of course, has been with Brady the entire way. But his resumé was sketchy after a five-year stint as the Browns coach in the early 1990s, when his teams finished only once with a winning record. But since taking over the Patriots in 2000 and going 5-11 in his first year, Belichick has never lost more than seven games in a season.
The Patriots' last 10 playoff appearances have included a first-round bye. When his players are asked about Belichick and when opposing coaches are asked about his greatest attribute, they point to his remarkable consistency.
"The ability to continue to show, regardless of the personnel and regardless of the coaching staff . . . and players that have come and gone, too, they've maintained the consistency of championship-level play, and that's Bill," said Seahawks coach Pete Carroll, who is attempting to win his second straight Super Bowl. "That's Bill's direction and the leadership, and I think that that's something that anybody in our world would like to be able to share and understand."
But you can't mention Belichick's accomplishments without including "Spygate." In 2008, the Patriots forfeited a first-round draft pick and Belichick was fined a maximum $500,000 when the league concluded after an investigation that the team had videotaped defensive coaching signals in a 2007 game.
Belichick apologized but has never been remorseful. Many believe he had been illegally taping teams for years, and ex-players such as former quarterback Kurt Warner, whose Rams lost to the Patriots in Super Bowl XXXVI, said that he still has a "sliver of doubt" and that the Patriots' legacy has to include the scandal.
"I don't know how you can't, just because you know that it's there," Warner said. "It's the most unfortunate part of this whole thing because I don't think that, in and of itself, made these two guys a great coach and a great quarterback. I don't think that should define their legacy as a whole.
"But I'm sorry, when you play outside the rules and people know it, it's always going to define at least a part of you. Maybe the point is it should affect Belichick more than it should affect Brady."
Brady's reputation, however, has been called into question after the NFL launched an investigation into whether the Patriots were playing with footballs that were purposely deflated in the AFC championship game two weeks ago vs. the Colts.
Brady and Belichick - and even Patriots owner Robert Kraft - have denied any wrongdoing. But the week leading up to the Super Bowl has been conducted under a cloud of suspicion about what really occurred and how the league has handled its investigation.
Belichick, a master motivator, is surely using the controversy to inspire his players. He has often come off as a taciturn public figure. His monotone news conferences are legendary. But he has occasionally let his guard down.
On Friday during a news conference with Carroll, he spoke of his father, Steve, the former Navy assistant coach and scout, who had the most influence on his coaching. He mentioned how his 84-year-old mother, Jeannette, would be watching Sunday from Annapolis, "yelling at the TV set all game."
But it's his staying true to his philosophy as the league has changed that many of his players say they admire the most.
"I don't think there is much that's changed from his personality or his coaching style," Brady said. "He has high expectations for our team. . . . So he's always coaching, he wants us to all be at our very best. It doesn't stop."
Naturally, that means Belichick has avoided answering questions about the past - both successes and failures - as he's kept his focus only on Sunday.
"I know someday we'll reflect back on that, hopefully, God willing," Belichick said. "For right now, it's all about Seattle."
Brady, seemingly near-perfect with his good looks and supermodel wife, Gisele Bundchen, also dodged questions about his past accomplishments. The Patriots won three titles in his first four years as a starter. He was very good then, but the Patriots defense was just as critical, if not more, in the victories.
He didn't start to carry the team and become the focal point until later. He said the last two Super Bowl losses have not discouraged him but only made him want it more.
"I have such an appreciation for it now," Brady said.
Warner said a defeat on Sunday would do nothing to take from Brady's place in the game among the very best quarterbacks.
"Look at Tom's Super Bowls - all of them have been decided by four points or less," Warner said. "He could be 5-0, he could be 0-5. . . . Tom's brought his team to the Super Bowl six times. No quarterback's even done that. Six times in, what, 13 years? That's unbelievable."
To some, the only argument is who was more responsible for each other's success, but that would ignore the greatness of both. They've been bound together for so long. The best Belichick could do to describe their relationship was to say they "played golf together for three days at Pebble Beach last year."
It's been mostly a working relationship. Many are under the impression neither has plans to retire any time soon and take up golf.