It's the game of the season, and we have a backstage pass. The Eagles versus the Chiefs. Go, Chiefs. And, Kelsey versus, Kelsey, on Monday night football. A rematch of last season's Super Bowl, where the Eagles lost to the Chiefs in a heartbreaker. The Kansas City Chiefs have won Super Bowl 57. This time, the Eagles. And the Eagles are on top. Getting revenge. We are behind the scenes of one of the most storied sports broadcasts of all time with that iconic theme music. On the biggest night of the year, millions watching as TV audiences shrink, football in the NFL to find the odds with huge audiences with touchdowns like this one. No, Dana Swift. No problem. As Travis, Kelsey celebrates, Nightline is with the team who brings it all together. The legendary broadcasting duo, Troy Akeman and Joe Buck.

For us, it's as big as.

It gets. As far as a regular-season game, I can't think of a bigger game that we've called in our 22.

Years together. And sideline reporter, Lisa Salter.

Is just electric. Every Monday night feels like the Super Bowl to me. These fans are going to be going nuts. People watching at home are going to be going nuts.

Troy Akeman is a Hall of Fame quarterback, and Joe Buck, a Hall of Famer too, for broadcasting.

You just can't lose. One of these two teams is going to win. One of these two fan bases is going to be thrilled. The other is just going to be heartbroken, no doubt about it.

Steve Ackles is the Vice President and producer of Monday Night Football.

When preparing for the game, you take the biggest storylines. Super Bowl rematch, quarterbacks, Kelsies, not to mention the two top teams in each conference, those two brothers and their parents, it's a major storyline. The Eagles.

And the Chiefs both at the top of their divisions and packed with star power. When you.

Have evenly matched teams like this in a big game, a lot of people are looking at these big plays and the throws down the field. But like a lot of games, it'll come down to who makes the fewest mistakes.

The quarterbacks, last year's League MVP, Patrick Mohomes, and the runner up, Eagles, Jaylen Hertz.

Patrick Mohomes and Jaylen Hertz have already, in the times that they've met, they've already just shown that there is no stage too big.

For them. But tonight, all eyes are on the Kelsey brothers. Jason, Kelsey, center for the Eagles, and his younger brother, Travis, tight end for the Chiefs.

I know they both love each other. I know that they're going to be rooting for each other to do well, but I know they're going to want to win. And that's just the way it is.

One of them, a finalist for people's sexiest man alive. The other, dating the most famous pop star in the world.

The NFL world has known the Kelsey Brothers for a long time because they've just been really great players and what they've contributed to really successful teams. But Taylor has put them on the map across the country, even non-football fans.

What other storylines are you watching?

What else could there be? Is there any other storyline other than Travis, Kelsey, and Taylor Swift? Are there any other storylines?

No. The Brothers have become two of football's biggest stars both on and off the field.

Welcome back, ladies and gentlemen, to New Heights.

They co-host the New Heights podcast, currently the number one sports podcast on Spotify.

Typically, you'll hear a quarterback have a verbal cadence. Well, if it gets too loud, they'll go to signaling to the center when they snap the ball.

Travis and Jason releasing a Christmas duet together last week: fairy tale of Philadelphia, part of Jason's charity Christmas album. Even the matriarch of the family, Donna Kelsey, getting spotlight attention too. Sitting down with my colleague, Will Reeve, yesterday.

Could you ever have imagined that you, yourself, Donna Kelsey, would be so famous?

No, not without them. That's for sure. What more could you want? It's just really special.

But for Mama Kelsey, she's just proud to see her boys once again facing off in one of the biggest games of the season.

I think as a mother, you always have the same nightmare and the same dream. The nightmare is that they're slinging fast food for the rest of their life. The dream is that they get the Nobel Peace Prize. Well, neither of those happen, thank God. They fall somewhere in between. They've pretty much reached the pinnacle of what they can do. So it's special.

Seen in box seats with Taylor Swift at Chiefs Games, she says her youngest son can handle the global attention.

I think Travis is embracing it as much as he can. He'll be good at it. He likes attention. He'll be fine. She's a very nice person.

Their relationship seeming to bring together two of the biggest and most passionate groups in the country, Swiftes and NFL fans. Do you think her coming to games, her dating a player, is it good for the NFL?

I think it is. The moreThe more the better, the more the merrier. And she moves the number in the NFL. There's a difference when she's at games and there's nothing wrong with showing that.

I think it's amazing that a league that really needs no help that she moves the ratings the way that she does. It really is quite a compliment to her. So hats off to her. I'm a fan of hers and I really respect what she's done and the businesswoman that she is.

Taylor has already been to three of Travis's games, and tonight she was expected to be here. But tragically, a 23-year-old fan died after her show in Brazil on Friday night. Taylor posting on Instagram. And due to scourging temperatures, she postponed her show to tonight.

But.

Even Taylor's absence can't dampen the excitement for Monday night football.

We want to show the ups, the downs, the big wide shots where you show the whole place going crazy. It all goes into the documenting of the game.

Derrick Moby is the director of Monday Night Football.

We have cameras that shoot the game coverage, which is how you see most of the play develop. We have handheld cameras roving around the field.

Sideline cameras, sky cameras suspended by cables, end zone cameras. He says over 60 cameras strategically placed around the field. There's no angle Moby can't see from inside.

The control room. I'll be looking at the monitor wall of all the cameras, the graphics. Steve Ackles will be sitting next to me giving the overall picture like, do we want to go to replay? Do we want to do this graphic?

It's just all about repetition and execution and all the planning that we have done. Let the game come to us. Try not to go too fast.

I think they're ready for tonight's game.

Troy Ackman and Joe Buck.

Standing by. When they kick that ball off, there's no feeling like it. I would assume there's no feeling like it for the people on the field, but there's also no feeling like it for us in the booth. It's exciting. It's new. It's fresh. It's fun. I can't wait for the game to happen.

Troy, how would you describe Eagles fans?

Crazy. Every team has their fans, but the Eagles's loyal fan base is, I think, different than the others.

I've been flipped off by more Eagle fans than any other fan base in the NFL.

You sound proud of that.

I.

Am. Joe, could you describe Chiefs fans?

Chiefs fans are riding high, and I think in their own way, passionate. Just as passionate. But I'm a Midwesterner. We do things a little different in the Midwest.

There.

Are two very devoted fan bases that are all in for this season and beyond.

Patrick Newhomes and Travis Kelsey have been the most productive quarterback.

Receiver combo. Lisa Salter's on the sideline, counting down to kickoff.

There's nothing like it being right down there on the field, seeing the passion, seeing the energy on every single play.

Fans tailgating, the excitement, building. Then finally, after all the preparation, game time. The game, a thriller. Eagles fans flying high tonight after the win. And for football fans, the magic of Monday night never ceases to amaze. What is it about football? It's so much more than just a game.

It's really not about the game. It's about the people playing the game.

Hi.

Everyone. George Stephanopoulos here. Thanks for checking out the ABC News YouTube channel. If you'd like to get more videos, show highlights, and watch live event coverage, click on the right over here to subscribe to our channel. And don't forget to download the ABC News app for breaking news alerts. Thanks for watching.