Tom Brady, Bill Belichick's legacy riding on Super Bowl XLIX

PHOENIX -- It has been a complicated week for the New England Patriots, and it will end with a game that holds complex implications. The undercurrent of the confusion, the derision, the bewilderment over the NFL's investigation into whether the Patriots tampered with footballs in the AFC Championship Game is a broader question about what we believe of the two men who have been unquestionably responsible for the Patriots' staggering success for nearly 15 years, but who are now inextricably freighted with a suspicion of dirty play.

What will emerge as the longest-lasting mark that Bill Belichick and Tom Brady make on the NFL? The meticulous attention to detail and the relentless push forward that has generated 14 winning seasons in 15 years and six Super Bowl appearances? Or the quiet whispers that maybe at least some of those victories are somehow tainted by a step across the line that separates getting an edge on an opponent from putting one over on them?

There is little question that this is a legacy-defining game for Belichick and Brady. Both are certain future Hall of Famers, but they are now moving in even more rarefied air. Win Super Bowl XLIX, and a strong argument can be made that they are the best coach-quarterback combination in history. They will have four titles, with a 10-year space separating the most recent two, a stunning testament to their consistency in an era of constant personnel turnover, much of it precipitated by Belichick himself.

Lose their third Super Bowl in a row, and the post-mortem becomes a bit more difficult.

"They're going to have to hear, 'Well, you never won after Spygate. You never won after DeflateGate,' " said Dan Shaughnessy, the longtime Boston Globe sports columnist. "'And you weren't the same after winning three out of four.' "

Shaughnessy admits those characterizations -- which could prevent the Patriots from getting enough credit for all they have accomplished -- might not be fair. But that is the reality for a franchise that has morphed from being a scrappy underdog in 2001 into a machine-like behemoth. A few months after the Patriots were found to have improperly videotaped opponents' signals in 2007, one league executive who had a good relationship with Belichick told me that Belichick, who had never spent much time endearing himself to the football fraternity or the league office, had long been viewed as a villain in the NFL.

That, the executive told me, was certainly exacerbated by resentment over Belichick's success. The behemoth is not to be understated.

Brady is the first player to start six Super Bowls, and a victory would tie him with Terry Bradshaw and Joe Montana for the most by a quarterback all time. Belichick is already the winningest postseason coach in history. He is tied with Don Shula -- who recently called him, not for the first time, "Belicheat" -- for most Super Bowl appearances. Together, Brady and Belichick have been to the AFC Championship Game nine times in the 13 seasons Brady has been the starter (not counting the full season he missed with a knee injury, when Belichick, in what might have been his finest coaching effort, coaxed 11 wins out of a Matt Cassel-led squad).

"It's incredible," said one opposing NFL coach who did not want to be named. Asked about the idea of any of the titles being tainted in some eyes, he replied, "I guess, but they've been to six. If they win, they would have four? Nothing matters. Armageddon could happen, and it wouldn't matter to New England."

That single-minded focus on moving on has been in place for years. Josh McDaniels, the offensive coordinator, has had two stints in New England, and he believes the lasting legacy of Belichick and Brady will be how consistently well they've done their jobs. They won their first Super Bowl together, when Brady was at the very beginning of his career. Now, he is nearing the end, with time running so short that Shaughnessy wonders if they will ever get another chance for a fourth title if Seattle wins Sunday.

"There is never a satisfaction with what happened in the past," McDaniels said. "There is always a forward-thinking vision with both of them. The season ends, we're not basking in the glory of how many victories we had or whatever we accomplish. We're looking forward to the combine and the draft like that."

McDaniels snapped his fingers and laughed. He said that in the locker room minutes after the AFC Championship Game ended, somebody was already having a conversation about last weekend's Senior Bowl.

"We understand this year's challenge is not our last game," McDaniels said. "Then we're on to next year's challenge. If you sit there and look at what you've done and you're satisfied with that too long, you get complacent. I've never seen either one of those two even have a hint of complacency in their job. The way they come in and work the next year like last year never even existed is a really neat thing to see."

That, in the end, may be the thing that defines Belichick and Brady more than anything else: Belichick's clear-eyed and often cold-blooded vision of roster building -- getting rid of a player a year too early rather than a year too late, and finding players to fill specific roles -- and Brady’s ability to meld his game to what is on hand. Even amid the controversies, the Patriots have never exhibited much regret over their past -- not about the missed opportunities nor the blemishes on their records. That has seemed to free and empower them, even this week, to keep churning ahead while everyone around them wonder how they do it.

This week marked the 15th anniversary of Belichick's hiring by owner Robert Kraft, the critical moment for a franchise whose existence now seems unimaginable without the coach. Whatever suspicions remain after the latest investigation is over, there is one unassailable truth in the NFL: Time keeps marching on, and Belichick and Brady never lose a step.

"You can't cheat your way into dominating a team sport and being competitive as long as we have with championships and being on the brink of world championships year in and year out over a 15-year span," said former Patriots cornerback Ty Law. "The proof is in the records, numbers and whatever else you want to look up. Twenty years from now, winning championships is the only thing people care about, and the only thing that matters. That can never be taken away."

Follow Judy Battista on Twitter @judybattista.