Move over, Tom Brady? Why Patrick Mahomes or Josh Allen could be NFL's next passing king

Football historians may one day look at the rivalry between Buffalo Bills QB Josh Allen and Kansas City Chiefs QB Patrick Mahomes with the same fondness they hold for those epic Tom Brady-Peyton Manning battles. On Sunday, the QBs will meet in a reprise of their epic AFC Division Round playoff game from last season.

Allen and Mahomes have a long way to go to solidify themselves as a rivalry as dynamic as Brady-Manning. But they might have a better shot at passing Brady as the all-time passing yards king.

Mahomes and Allen are already outpacing Brady in total passing yards through a similar number of games. Data from Stat Head shows that during their first five seasons, Allen played in 66 games and passed for 15,765 yards; in 63 career games, meanwhile, Mahomes had 18,991 passing yards.

Through Brady's first 64 games, he had 13,925 passing yards, an average of 224.6 yards per game. During the past 16 seasons (259 starts), he has averaged 278 passing yards a game. Overall, Brady has thrown for a ridiculous 85,929 yards, far more than Drew Brees, who's second.

Brady is widely believed to be retiring after this season and begin collecting the $375 million owed to him as part of his broadcasting deal with Fox. If that's the case -- and Brady performs like he has his past two seasons with Tampa Bay -- he'll finish his career with about 89,495 yards.

It's a steep mountain to climb, but Allen and Mahomes are in a position to supplant Brady as the passing king someday.

Longevity is the key, and with the league doubling down on QB safety, both should have long careers. There's some concern about Allen's long-term projections as he's shown a fearlessness as a runner that isn't traditionally conducive to an extended career. As he gets older, he'll almost certainly take fewer risks in the running game. The 17-game regular season schedule could aid Mahomes and Allen, too.

Of the two, Mahomes is the better bet to pass Brady. His sack rate for his career is just 1.5 percent. Through his first five seasons, Mahomes has averaged 37.2 pass attempts per game, roughly six more than Brady (31.5) over the same span.

Removing his start in 2008 when he suffered an ACL tear, Brady has attempted 11,513 passes over 320 games, an average of roughly 36 attempts a game. 

So, how long would it take Mahomes to pass Brady? Assuming the NFL schedule stays at 17 games a season (it might be 18 eventually) and using Mahomes' per-game average of 299.8 yards as a baseline, the Chiefs' QB would pass Brady in 2035. Mahomes will turn 40 that season.

That's far enough away that Mahomes has a couple of presidential cycles until he can seriously think about passing Brady. Don't bet against him. He often makes the impossible possible, like this pass against the Colts: