There is no relationship in sports as critical to success as the quarterback and his head coach. Yet, it is often among the most contentious. Whether it’s butting heads over play-calling, strategy, power, or a personality clash, many of the NFL’s best teams were led by a head coach and quarterback, who could barely stand each other.

Think Bill Belichick and Tom Brady, Phil Simms and Bill Parcells, John Elway and Dan Reeves, Troy Aikman and Barry Switzer, Aaron Rodgers and any head coach he played for. Yet, unlike those volatile partnerships, Kansas City head coach Andy Reid seems more like Patrick Mahomes’s favorite uncle than his head coach. Their genuine respect and admiration for each other have put the Chiefs on the verge of an unprecedented three straight Super Bowl victories when they meet the Philadelphia Eagles on Sunday at the Superdome at New Orleans.

“He’s the best,” Mr. Mahomes said of his head coach. “Obviously, he’s one of the best coaches of all time and one of the best offensive minds. The way he is able to continue to bring us new plays and bring us new motions to pique our interest every week of the season is one of a kind. I think the person is what really makes him who he is. It doesn’t matter who the quarterback is or who is on the team they all love him because he’s truly a good, genuine person. He cares more about me the person, than the player.”

A quarterback and head coach liking each other isn’t mandatory for winning a championship. Mr. Belichick and Mr. Brady won six together before Mr. Brady left to win another at Tampa Bay. Mr. Simms and Mr. Parcells also lifted the Lombardi Trophy even though a clip of them screaming at each other on the sidelines is part of football lore.

Sometimes the static between a head coach and quarterback is calculated to keep a team on edge, knowing if the quarterback can be subject to a verbal blasting anyone else could be next.

There’s none of that with the Chiefs. Gary Myers, who is a long-time NFL writer and author of the upcoming book, Brady vs. Belichick: The Dynasty Debate, said the relationship between Messrs. Mahomes and Reid is unique.

“You never see any friction between them, at least publicly,” Mr. Myers told The New York Sun. “I think they’re grateful to have each other. Mahomes is a generational talent that is doing things we haven’t seen done before and Andy just seems to be getting better and more creative the longer he has Patrick.”

Mr. Myers, who also wrote “Once a Giant,” said the relationship between Mr. Simms and Mr. Parcells worked because “they seemed to feed off each other by getting in each other’s face.”

Mr. Simms told Mr. Myers how there was constant pressure to please Mr. Parcells. “Phil told me there were days he went home from practice and was anxiety-ridden from having to be perfect and withstanding all the criticism and getting yelled at,” Mr. Myers said. “I have a feeling Mahomes doesn’t go through that.”

Despite being on the threshold of winning three straight Super Bowls, Mr. Reid was once criticized for not being able to win the big game. He made nine playoff appearances and went to four straight NFC Championships games during his 14 seasons as the head coach at Philadelphia. He reached Super Bowl XXXIX at the end of the 2004 season where they were beaten by the New England Patriots, 24-21.

The Chiefs hired him in January 2013 and can’t seem to lose since drafting Mr. Mahomes with the 10th overall pick in 2017. After playing behind Alex Smith for one season, Mr. Mahomes became the starter in 2018 and has taken the Chiefs to seven straight AFC Championship Games and now a fifth Super Bowl.

Mr. Mahomes’ unique blend of a great arm, great mind, and competitive spirit coupled with Mr. Reid’s creative offensive schemes have made the Chiefs football’s latest dynasty. The coach gives the quarterback plenty of credit for the team’s success.

“He spends a lot of time at the game and making sure all the crazy formations that we have that he can digest them first and be able to spit them out in a short period of time,” Mr. Reid said. “He’s able to see and anticipate what the defense is going to do. You’ve got to know where their guys are and you’ve got to know where your guys are. He’s able to digest all that. He’s a sharp kid.”

There’s a lot of conversation today about who deserves more credit for the Patriots winning six Super Bowls: Mr. Belichick or Mr. Brady. Years from now, when they talk about the Chiefs they’ll mention a quarterback and coach who won championships and actually got along doing it.