Sometimes it takes a setback to realize you never should underestimate the value of a good thing.

It is a lesson CBS - which will celebrate 50 years of broadcasting the NFL this fall - learned the hard way during the mid-1990s, when things weren't so golden.

On Dec. 18, 1993, CBS was outbid by upstart Fox for the rights to NFC games, ending CBS' 38-year reign as the NFL's premier network provider. CBS had televised NFC games since the NFL and AFL merged in 1970, and had broadcast NFL games since Sept. 30, 1956.

Fox, despite its fledgling sports department, was backed by the deep pockets of founder Rupert Murdoch. He offered the NFL $1.6 billion over 4 years for exclusive rights, significantly more than the $290 million a year CBS offered to retain the NFC.

Seemingly as if to kick CBS while it was down, Fox also scooped up multiple members of CBS' broadcast talent, most notably booth legends Pat Summerall and John Madden. Summerall, who gave 31 years of his illustrious NFL broadcasting career (1962-1993) to CBS, vividly remembers the day it all came to an end.

"I hated leaving CBS, it was one of the saddest days of my life," said Summerall, who along with Madden joined Fox shortly thereafter. "Thank goodness [Fox] offered me and John the job together. At first, Fox was not like what we were used to at CBS, which made for a weird transition. At some points there in the early going, we didn't even know if we'd get on the air."

For Madden, it felt a little like betrayal. A former Super Bowl-winning coach of the Oakland Raiders, Madden got his start at CBS in 1979 and honed his craft in a booth with Summerall, one they shared from 1981 to 1993. They worked five Super Bowls and became an iconic duo that to this day has "yet to be replicated," according to Sean McManus, president of CBS Sports and CBS News.

"I thought it was just a rumor, because you know news like that always starts out that way," Madden said. "You say there is no way, but when it happens you really are just in a state of shock. CBS just brings back so many great memories. I mean, they were the ones to give me my first opportunity, so I felt like I had a loyalty to them."

The pair soon found their niche on Fox and turned the upstart network into a sports powerhouse. Madden, who retired last season after 30 years, spanned four networks (CBS, Fox, ABC, NBC) and 11 Super Bowls, and garnered 16 Emmy Awards. Summerall, who retired in 2002 because of health issues, is regarded as one of the great voices of professional football.

"I think it's clear that those two are legends," said CBS broadcast analyst and former Giants quarterback Phil Simms. "When I played for the Giants, it was CBS that covered most of those games and Pat and John were an immense part of that. Losing those two was gut-wrenching."

Between 1993 and '97, CBS bled money as it banked on shows and other sports programming that barely made a dent in the Nielsen ratings. CBS, which had been regarded as the face of the NFL since 1956, now took a back seat to ABC, NBC and Fox.

In 1996, McManus was named president of CBS Sports and immediately sought to return the NFL to "its home." In 1998, he offered the NFL, led by commissioner Paul Tagliabue, $4 billion over 8 years for the rights to AFC games. At the time, the NFL's contract with NBC for AFC games was nearing its end. The NFL gave NBC first crack at a chance to counter CBS' offer.

"I was told by Paul Tagliabue that NBC had the right to get it back and that he would contact us and let us know their decision," McManus said. "I sat around with fingers crossed all weekend. I didn't sleep and I cringed every time the phone rang thinking it was him . . . Finally, Monday morning Paul called and said they were sending someone over with paperwork. I remember that as being the longest Sunday of my life."

On Sept. 6, 1998, close to 1,700 days since CBS' last NFL broadcast, "NFL Today'' host Jim Nantz welcomed fans back to the NFL on CBS. Today, the network holds exclusive rights to all AFC matchups and the Super Bowl. Just as before, CBS kicks off each Sunday with an installment of "NFL Today," now hosted by James Brown, going into its 42nd season.

In the booth, Nantz and Simms enter their sixth season together on CBS, as the network continues to evolve and expand amid blackout restrictions, flex scheduling and constant competition for ratings.

Which, all things considered, are welcome concerns.

"We have issues we contend with, like blackouts, but we have dealt with them in the past, and when the economy gets better, it will get better," McManus said. "This is a time to celebrate at CBS; 50 years of televising any sport is amazing in itself and we can say we did it."