Brady vs. Mahomes: Why legacies are at stake in the Super Bowl

The story of Super Bowl LV is a simple one: Tom Brady vs. Patrick Mahomes.

Sure, two quarterbacks who will never share the field together won't entirely determine whether the Tampa Bay Buccaneers or Kansas City ultimately wins.

Maybe K.C.'s banged-up offensive line prevents Mahomes from having a shot. Maybe Tampa Bay's defence takes over. Maybe one of the many star receivers in the game shines.

But let's be honest: this year's Super Bowl will be remembered for its quarterbacks.

In one corner there's 43-year-old Tom Brady, a six-time champion who, to the surprise of some, left New England — for 20 seasons, the only NFL home he'd ever known — for a fresh start in Florida.

In the other corner there's 25-year-old Patrick Mahomes, the reigning champion who signed a 10-year, $503-million US contract extension with Kansas City in the off-season.

Mahomes, who won MVP in his first season as a starter and Super Bowl MVP in his second, is regarded by many as the next challenger to Brady's claim as the greatest quarterback ever.

WATCH | Tom Brady vies for 7th title in Super Bowl LV:

If Mahomes's team, favoured to win, comes through, it'll leave him four Super Bowls shy of Brady's career total. But if Brady wins his mind-boggling seventh, at 43 no less, the gap would become nearly impossible for Mahomes to overcome.

Imagine if Michael Jordan ever stared down LeBron James in NBA Finals. The never-ending GOAT debate would have a lot more clarity.

"The Super Bowl's the Super Bowl. Being able to go up against one of the greatest, if not the greatest, quarterback of all time, in his 150th Super Bowl, I mean, it's going to be a great experience for me," Mahomes said on Monday, sarcastically pointing out Brady's penchant for appearing in the NFL's biggest game.

Tale of the tape

Brady and Mahomes have gone head-to-head twice before, with each winning once.

Their marquee matchup came in the AFC championship game two seasons ago when Brady was still a Patriot. In that game, New England jumped to a 14-0 lead, with Kansas City unable to score in the first half.

But Mahomes flipped the script in the second, leading his team to 31 points, including three touchdowns and the game-tying field goal in the fourth quarter. When a controversial off-sides call against K.C. negated what would have been a game-ending interception of Brady, the game went to OT.

In the extra frame, the Patriots won the coin toss and promptly marched for a touchdown. Mahomes never got the ball. Advantage: Brady (despite two picks to Mahomes's zero).

The second matchup came in November, when Mahomes boosted K.C. to a 17-0 lead and Brady's second-half comeback attempt fell three points short.

While Brady's line of 345 yards, three touchdowns, and two interceptions was nice, Mahomes responded with a whopping 462 yards, three scores and no picks. Advantage: Mahomes (despite the oddly quiet finish).

But don't call Super Bowl LV the grudge match: Brady recently left the door open to playing past 45.

The sixth-round pick out of Michigan in the 2000 draft, Brady won Super Bowls in two of his first three seasons as a starter — a feat never matched, unless Mahomes wins on Sunday.

He spent 20 seasons in New England paired with future Hall of Fame coach Bill Belichick. Brady and Belichick were inextricable from each other — until the former jetted to Tampa Bay.

A seventh Super Bowl win would retroactively give Brady more credit for the first six. He didn't need Belichick to reach Super Bowls, it turns out.

Regardless, Brady's resume is impeccable. Three MVPs, 14 Pro Bowls, an NFL-record 581 passing touchdowns, second all-time in passing yards. A one-way ticket to the Hall of Fame.

He's played in nine Super Bowls and won two-thirds of them, in sometimes incredible ways (see 2017's 28-3 comeback victory against the Atlanta Falcons).

Challenger to the throne

Mahomes, meanwhile, is 44-9 — including 6-1 in the playoffs — as an NFL starter. In all but one of those playoff games, Kansas City scored at least 31 points, and in the one game it didn't; Mahomes left in the third quarter with an injury.

In the regular season, Mahomes has already compiled 14,152 passing yards and 114 touchdowns. He's also added 808 yards with his legs — within 200 of Brady's 21-year total.

On the surface, Mahomes is more talented than Brady ever was. He has a stronger arm and more mobility, and his dizzying array of arm angles (you may have heard his father was an MLB pitcher) puts his athleticism on full display.

Brady is one of the smartest QBs of all-time, a savant at picking apart a defence with quick, short passes in his later years. The move to the Buccaneers renewed his deep attack and blessed him with the top receivers he lacked by the end of his time in New England.

WATCH | Bring It In's Super Bowl preview:

On Sunday, Brady has a chance to become the first QB to win a Super Bowl at home. When you play in 18 per cent of Super Bowls ever, that's almost bound to happen.

He has a chance to affirm his status as leader of the Patriots dynasty, as more than a product of Belichick. He's already defying odds playing football at 43, but winning a Super Bowl at that age would be a different story entirely.

He's already cemented his GOAT status, but a win Sunday would put him in an almost-unreachable level.

In his way is Mahomes, a possible heir to the throne who may only have a shot to eclipse Brady with a win on Sunday.

Mahomes has a chance to rewrite NFL history.

Legacies are at stake in Super Bowl LV.