Cheers (https://jacksonupperco.com/2016/01/19/the-ten-best-cheers-episodes-of-season-one/) of course, predated (https://www.bostonmagazine.com/news/2016/09/29/cheers-premiere/) The Cosby Show (https://www.sun-sentinel.com/news/fl-xpm-1992-04-30-9202050833-story.html) by about two years (https://jacksonupperco.com/2016/07/19/the-ten-best-the-cosby-show-episodes-of-season-one/). It was Cheers (http://nostalgiarush.blogspot.com/2014/06/random-thoughts-other-diffrent-strokes.html) that you could easily argue, woke up the viewing audience and established the then 3rd place NBC as the fresh place for sitcoms. The Cosby Show (https://www.sun-sentinel.com/news/fl-xpm-2002-05-19-0205230247-story.html) may have cemented (https://www.latimes.com/archives/la-xpm-1995-02-23-ca-35153-story.html) NBC's turn around (https://apnews.com/de944a090a6343135a763746ce8b5031), but Cheers you could say, actually started said turn around in the first place.

Hill Street Blues was actually the cornerstone. It finished No. 27 Thursday night in 1981-82.

Hill Street moved up to No. 21 in 1982-83. The rest of the night - Fame, Cheers, and Taxi - was admired but not watched.

For 1983-84, they put Cheers and Hill Street together, and they finished Nos. 34 and 32, respectively. They made a crazy decision putting the new We Got It Made in front of Cheers. By the summer, though, they had strung together Family Ties, Cheers, Night Court, and Hill Street.

Then in 1984-85, Cosby came on Cosby No. 3, Family Ties 5, Cheers 12, Night Court 20, Hill Street 30.

1985-86: Cosby 1, Family Ties 2, Cheers 5, Night Court 11, Hill Street 33

So Hill Street Blues was really the cornerstone. Cheers also did very well, moving from the last-ranked show in its first season to just outside the top 30 in its second. And then the network smartly got Family Ties and Night Court with them.

Cosby, of course, was a ratings monster, up with Lucy and All in the Family. It's just the way things are that one entity gets all the credit when others also chipped in. In this case, it's Cosby.

Ah, the original Thursday night, Must See TV!!!! Good times!!!

Because Cheers didnt become a top then show until the 4th season

If we're talking sitcoms, I think it was actually Diff'rent Strokes that saved NBC. The 1978-1979 season had NBC with just four series in the top 30: Little House, CHIPS, the Monday Night Movie, and Diff'rent Strokes. By the time Cheers and the Cosby show debuted, NBC was inching its way back into the top 30, with DS and The Facts of Life already in the top 30.

If we're talking sitcoms, I think it was actually Diff'rent Strokes that saved NBC. The 1978-1979 season had NBC with just four series in the top 30: Little House, CHIPS, the Monday Night Movie, and Diff'rent Strokes. By the time Cheers and the Cosby show debuted, NBC was inching its way back into the top 30, with DS and The Facts of Life already in the top 30.

Yup DS wasnt too long after Sanford and Son ended and that was the turning point.