When Super Bowl 50 is played early next month, it will easily be the most watched televised event of the year, with roughly a third of American households tuning in.
It wasn't always that way. After the first Super Bowl was played back in 1967, NBC and CBS, the networks that broadcast the game, erased the tapes.
It's been long thought that game was lost forever — until now.
Turns out the NFL's own production unit was also filming that game. It has now stitched together their archival footage with NBC's radio broadcast by Jim Simpson and George Ratterman.
The entire game will air again Friday for the first time since 1967, on NFL Network.
NFL Films senior producer David Plaut says they spent months scouring NFL archives looking for the footage and then they had to put it all together.
"I likened it to a jigsaw puzzle," Plaut says.
It's a puzzle with145 pieces, one for each play between the National Football League's Green Bay Packers and the American Football League's Kansas City Chiefs.
While pro football back then was still way less popular than baseball, boxing and even college football, Plaut says the teams on the field were still pretty impressive.
"You had a game where you had 14 future hall of famers, two hall of fame coaches, a lot of great, immortal players who many people have never seen play and at least for one evening, you're going to see them come alive again," he says.
Plaut says fans watching Super Bowl I: The Lost Game will probably notice differences and also similarities between the game now and then.
"The athletes are not as big, they're certainly not as fast, but the game is fundamentally played in the same way," he says. "Where the Super Bowl is different is in the way that it is presented. It is so much more of an event of entertainment and spectacle than it was."
Think about the halftime show. Back then, for example, it was less Beyonce and Coldplay and much more marching bands.
Dave Robinson played in that original Super Bowl. He was a linebacker for Green Bay. He says that walking into the stadium with legendary Packers coach Vince Lombardi felt historic.
"Vince said, 'Man, football's has come a long way from when I used to play in cow pastures,' and I said 'Well, you're right, Coach.' He thought that this was a long way, but if he could see the Super Bowl today, with all the grandeur," he says.
He probably wouldn't believe it.
Spoiler alert: the Packers won that first Super Bowl, beating the Chiefs 35 to 10.
On Friday night, Robinson gets to relive that glory.
"I've always said, I wish they saved those tapes of Super Bowl I. Now I'm going to have my own copy because I'm going to tape it," Robinson says. "I really can't wait to see it."
His prediction for this year's Super Bowl?
"Kansas City versus the Green Bay Packers. Wouldn't it be phenomenal to have those two teams play Super Bowl L, after having played Super Bowl I? The league would come full circle," he says.
Those two teams, while they're low seeds, are both still in the playoffs, so that could happen.