Today marks the 50th anniversary of a moment that forever changed television coverage of the National Football League – it is the anniversary of the infamous “Heidi Game.”

The contest pitted the New York Jets against the Oakland Raiders, two bitter rivals in the American Football League, the upstart league in the pre-NFL merger era. The Jets, led by quarterback Joe Namath, took a 32-29 lead in the hard-fought game with less than a minute to play.

That’s when trouble ensued. NBC-TV, which was televising the game, had scheduled a presentation of Heidi, the tale of a young girl’s adventures in the Swiss Alps, for 7 PM ET. That was usually considered a safe time slot for regular programming, given that most pro football games ran about an hour per half in that era.

But this Jets/Raiders game ran slower than expected, and exceeded its scheduled three-hour time slot. So, as per pre-arrangement, the Jets/Raiders game went to commercial, only to return to the start of Heidi at 7 PM instead of the game, with no explanation to the many fans watching in the New York market who were flummoxed that they couldn’t see the end of the game.

Apparently, Timex had bought a $700,000 sponsorship of the entire Heidi show, a hefty sum in 1968, and had emphasized that it had to start on time.

Of course, the Raiders compounded the football fan misery by scoring two touchdowns in the remaining seconds of the game, incredibly winning 43-32. The NBC switchboards lit up with angry callers once the game was no longer visible, jamming the lines and allegedly preventing a call from former NBC president Julian Goodman to reach head of broadcast operations Dick Cline that the close game should be allowed to finish on the network.

Cline told Newsday this week that the switchboard was also flooded by those wanting to know if Heidi would be on schedule. “There were equal numbers of people calling in to find out if ‘Heidi’ was going to be on time as there were football fans who wanted to know if we were going to see the end of the game,” Cline said. “They collided on a switchboard that blew up.”

In a 1997 media survey, the Heidi game was named the most memorable of the NFL’s first 10,000 regular-season games. The fumble by television executives is remembered today as one of the biggest gaffes in television history, and led to a new rule that all NFL games would be televised to their conclusion.