The 2021 Super Bowl is like if LeBron James got to face Michael Jordan in an NBA Finals.
The 43-year-old Tom Brady of the Tampa Bay Buccaneers and the 25-year-old Patrick Mahomes of the Kansas City Chiefs could each have a rightful claim to the title of “Greatest of All-Time” (GOAT) when they retire. Brady has made his case by amassing individual accolades and team victories over a two-decade career, whereas Mahomes is the owner of a plethora of mind-boggling statistical accomplishments.
Brady is the only quarterback to start a Super Bowl after turning 40 years old, and by Sunday night he’ll have done it three times. On the flip side, Mahomes will become the youngest quarterback to ever make his second Super Bowl appearance.
Because the age gap between the two stars is so large, it’s difficult to make statistical comparisons. Each stands out in his own way. For example, Mahomes has won 83% of his NFL starts (Brady ranks second in the modern era at 77%). Brady, though, has racked up 263 career wins in the regular season and playoffs combined—so many that second place Peyton Manning could unretire, rip off three straight undefeated Super Bowl-winning seasons and still fall short.
In fact, among the 163 quarterbacks who have started at least 50 games since 1970, Brady is first in virtually every cumulative career QB ranking (shown along the x-axis below), while Mahomes is first in every rate statistic for measuring QB performance (shown along the y-axis).
In the above charts, Mahomes sits head-and-shoulders above everyone else. Of course, he has the benefit of playing in the highest-scoring era of NFL history, one in which passing is more frequent, more celebrated and further encouraged by recent rule changes. How do Mahomes’ stats stack up to those of other all-time great quarterbacks relative to the competition of their respective eras?
One comprehensive quarterback metric we can use is Adjusted Net Yards Per Attempt (ANY/A), which is simply a variant of Yards Per Attempt that gives quarterbacks additional credit for touchdowns and demerits for interceptions and lost yards via sack. To compare across eras, however, we’ll use ANY/A Index, which sets the league average for any given season to 100.
If he continues playing near this level for the rest of his career, Mahomes will have a strong statistical case for being the greatest quarterback of all time, but in some fans’ eyes, winning is all that matters. Pick a Super Bowl since Brady’s first career start and pick a random two-point conversion from the 2020 NFL season; there’s a greater chance Brady appeared in the chosen Super Bowl than that two-point conversion was successful.
He’s already outpacing Brady statistically, but if Mahomes wins his second ring in his first three seasons, he’ll be well on his way to catching Brady in the jewelry department as well.