Kansas City Chiefs quarterback Patrick Mahomes trails just one NFL QB in terms of cumulative grade since the start of the 21st century, and that Hall of Fame signal-caller is Peyton Manning, not Tom Brady.

In a document shared with Heavy, Pro Football Network ranked the top 25 quarterbacks of the 21st century, but there was a catch. This ranking went strictly by QB+ grade.

Pro Football Network described QB+ as “a formula that assigns a score and letter grade to each quarterback’s individual performance. The metric blends stats like success rates when pressured, third-down conversion rate, and pocket production. The added wrinkle? Quantifying ‘clutch.’ We used timeliness-based stats to account for score and situation.”

After PFN compiled all that data, Mahomes placed No. 2 overall, with Manning as the 21st-century champion — so far.

Mahomes is still playing, so his cumulative grade could still rise and fall, while retired quarterbacks like Manning and Brady’s grades (ranked sixth highest) will remain static. They could move up or down the list, too, but only if current NFL QBs either fall below them or surpass them.

“Mahomes is only 29, but he already has a case as a top-three quarterback of all time,” PFN wrote, noting the Chiefs superstar’s Super Bowl titles, MVP awards and “17-4 playoff record.”

“What sets Mahomes apart is his ability to elevate in the biggest moments,” the NFL analysis site continued. “His playoff passer rating (105.8) is higher than his regular-season mark (103.5). He holds the highest close-game EPA per dropback in QB+ history, and his 47.5% conversion rate on third and fourth downs is the best of any QB since 2000.”

“Mahomes’ poise under pressure is rare,” they concluded. “His -0.1 pressured EPA/DB ranks among the best, and his +0.34 from a clean pocket is elite.”

Pro Football Network detailed Peyton Manning’s grade, too, as well as Tom Brady’s, and you can find the full list via this link (including a few unexpected inclusions). For Manning, they wrote:

No quarterback in NFL history has won more MVPs than Peyton Manning, who claimed the honor five times over his 18-year career. Known as the ‘Sheriff’ for his command at the line of scrimmage, Manning lived up to the hype after being selected No. 1 overall in the 1998 NFL Draft.

Manning revolutionized the position with elite accuracy, pre-snap reads, and relentless preparation. He led some of the league’s most dangerous offenses, including the 2013 Denver Broncos, where he set single-season records for both passing touchdowns (55) and yards (5,477). He finished his career with 71,940 passing yards and 539 touchdowns, ranking third all time in both categories.

Manning’s advanced metrics are elite, posting a near-perfect 99.9 QB+ score. His +0.23 career EPA per dropback is the best of any quarterback in the 21st century, and in close games, his +0.26 EPA/DB ranks second only to Patrick Mahomes.

Manning’s playoff résumé isn’t as pristine — 14-13 record with an 87.4 passer rating — but he proved he could win when it mattered. He became the first starting quarterback to win Super Bowls with two different franchises. Two titles, seven first-team All-Pro honors, and 14 Pro Bowls later, Manning now has a bust in Canton.

One more former Chiefs quarterback made this elite top-25 NFL quarterback ranking: 88-game KC starter Trent Green.

“Trent Green’s sample size isn’t as large as most other retired quarterbacks on this list,” PFN noted. “He made 113 starts and finished with a 56-57 record, having missed nearly two full seasons early on. Green also entered the league at age 27, and by the time QB+ was introduced, he was already 30.”

“Green finished his 11-year career with 28,475 passing yards, 162 touchdowns, and 114 interceptions,” the site went on. “Outside of a league-leading 5.5% touchdown rate in 2002, he didn’t top any major statistical categories — unless you count leading the NFL in picks in 2001 (24).

“Green ended with a +0.14 EPA per dropback, with his most notable metrics being 7.3 net yards per pass attempt and a +0.37 EPA per rush on 109 designed runs.”

Mahomes and Green were the only 21st-century Chiefs QBs to make this list, although Rich Gannon (who played for Kansas City prior to the turn of the century from 1995 through 1998) graded out 15th for his late-career resurgence with the then-Oakland Raiders.