The Kansas City Chiefs agreed to a contract extension with quarterback Patrick Mahomes worth $450 million, the largest contract in American professional sports. Why did they take the plunge? Here are 10 reasons:

10. The 2017 10th overall pick is the fastest player in NFL history to 75 touchdown passes (30 games), surpassing Dan Marino (32 games). And he already has the most touchdown passes by a homegrown quarterback in Chiefs history.

9. Mahomes accounted for 12 touchdowns (passing and rushing) in the 2019 postseason -- the most in a single postseason in NFL history.

8. He completed a 44-yard pass to Tyreek Hill on third-and-15 in the Super Bowl to help the Chiefs' comeback to win. On third-and-15 or longer last year, he was 13-of-17 for 299 yards and 3 TD -- 17.6 yards per attempt.

7. He’s not exactly known as a runner, but he’s scrambled for more yards and first downs than any quarterback in the NFL since returning from injury in Week 10 of last season, including playoffs -- yes, better than Lamar Jackson and Russell Wilson.

6. He has an absolute cannon for an arm. He has 22 touchdown passes of 20 or more yards downfield in the past two seasons, the most deep-ball touchdowns in the league.

5. Mahomes has an NFL-best 73 Total QBR under pressure since the start of 2018. The league average is 20.

4. One reason he’s so good under pressure -- throwing on the run. He has 23 touchdown passes on the run in the past two seasons -- eight more than anyone else, including during the postseason. He actually had more touchdown passes on the run last postseason (5) than the rest of the NFL combined (4), per NFL Next Gen Stats.

3. He’s played 36 games in his career, including postseason, and never lost by more than one score or posted a Total QBR below 50 in a game. In other words, he’s never had a below-average game (QBR 0-100 scale). It’s the most consecutive games with a QBR of 50 or more to start a career (36) since the metric was first calculated in 2006. (The next-highest is 12 by Dak Prescott.)

2. Mahomes was 5-0 in 2019 when trailing by double-digits, the best record in a season in NFL history, including postseason. He’s also the first quarterback in NFL history to win three straight games by double-digits after trailing by double digits, including postseason. He accomplished that streak during last season's playoff run.

1. He became the youngest quarterback (24) in NFL history to win both an MVP and Super Bowl title, surpassing Brett Favre. He also surpassed Tom Brady as the youngest quarterback to win Super Bowl MVP.