I know AITF was the #1 series between 1971-1976 and shows don't stay on top forever, but what caused the huge drop in the 1976-77 season where it plummeted to #12? Shows do go downhill with age (Maude and Sanford And Son both also plunged out of the top 10 to #31 and #27 respectively, Sanford ended this season and Maude fell even further down in its last season) and I know this was the era of shows like Happy Days and Laverne And Shirley, but what makes the plunge in season 7 more unexplainable is the fact that for season 8, it bounced back up to #4 behind only three ABC Tuesday mainstays and has several episodes now regarded as all time classics (the rape episode Edith's Crisis of Faith and when Mike and Gloria depart). I recently bought the complete series and haven't gotten that far down, but I'm curious what made season 7 so unremarkable that it slid out of the top 10 and had no real classic episodes when it was able to bounce back up the next year.

It was moved to Wednesday briefly at the beginning of the season and that caused the drop. It was moved back to Saturday after a few months and things stabilized. Then it moved to Sunday for season 8, where it stayed for the rest of its run.