Tom Brady, the New England Patriots' 41-year-old quarterback, is the reigning MVP, has thrown 500 touchdown passes, has won five Super Bowls and will be looking to become the first quarterback to win 200 regular-season games in Sunday night's game against the Kansas City Chiefs in Foxborough, Mass.
Yet he will share the spotlight with Kansas City's 23-year-old quarterback, Patrick Mahomes, who has started just six NFL games in his career.
Mahomes has thrown a league-leading 14 touchdown passes with just two interceptions this season while leading the Chiefs to a 5-0 start and directing an offense that averages 35.0 points per game, which ranks second in the NFL.
Brady has 12 touchdown passes with six interceptions for the Patriots, who are 3-2 and rank tied for ninth in scoring at 26.6 points per contest.
"I was a Cowboys fan when I was younger," Mahomes said, "so being from Texas, I wasn't necessarily a fan of him winning all the time. But you definitely respected his game and how he played. When you have that much success, it takes a bunch of hard work, so you respect that."
When Brady won his first Super Bowl, Mahomes was just 6 years old.
"I don't really remember those first few Super Bowls that he won," Mahomes said. "I remember the Super Bowl, the snow game and them kicking the field goal to win. But not until I got older and just seeing his successes year in and year out as I've gotten older, it is truly special to see all of that hard work pay off."
Mahomes ranks third-best in the Super Bowl era with 1,797 yards passing in his first six career games. His 14 touchdown passes rank tied for fourth.
"He can throw it, run it, does a good job of reading coverages, gets the ball to his playmakers in space and creates space for them so they can make a lot of plays," Patriots head coach Bill Belichick said.
Chiefs head coach Andy Reid knows Belichick will come up with looks Mahomes hasn't seen on film..
"He's the best at that," Reid said of Belichick. "He mixes and matches, and he does that whole thing. He can change up and give you a completely different look one week than the other. So you make sure that you've got plays that are good versus all and you go in and you play."
There is a comparison at another key position: tight end.
"Yeah, I mean, on my list, I would rank Kelce the best tight end in football. I know Gronk has been a great tight end for a long time. But, I mean, I haven't gotten to play with Gronk. I've gotten to play with Kelce, and I've never seen anyone be able to do the things that he's done," Mahomes said.
Gronkowski has 23 receptions, but that is only second on the team to running back James White, who has caught 32 passes for 270 yards and four touchdowns. White has also rushed for 110 yards, although New England's main rushing threat the past two games has been rookie Sony Michel, who gained 210 yards in consecutive wins over Miami and Indiana.
The main receiving threat for the Chiefs is Tyreek Hill, who has 27 receptions, nine of which have gone for more than 20 yards.
"Whoever the fastest player on anybody's team is probably isn't as fast as Hill," Belichick said.
Hill had seven catches for 133 yards and a touchdown in the Chiefs' 42-27 victory over the Patriots in last year's season opener.
The Chiefs started 5-0 last season and limped to the finish line with a 10-6 record that earned them a wild-card berth before losing their postseason opener to the Tennessee Titans.
The game against New England might indicate whether Kansas City will repeat that slide.
Belichick says the Chiefs' undefeated start this season is a result of their ability to jump out to early leads. However, he also notes they came from behind to beat Denver in Week 4.
"They've killed teams in the first quarter," Belichick said, referencing Kansas City's 59-9 advantage in the first quarter of games this season. "It looks like they can play in any situation they're in. That's why they're as good of a football team as there is in the National Football League right now. They're good at everything."
Reid won two out of three matchups against Belichick and the Patriots during his first five seasons in Kansas City.