Yabba, dappa dropped. 1966 spelled an all-too-familiar trend of parting with the previous era's successes. Several longstanding ABC veterans and three-year ventures were handed pink slips from the networks. Given newer sensations Bewitched and Batman were top-10 players, ABC decided to shake it up and remain competitive with 1st place CBS. The Tiffany Network continued with its perfect marriage between homespun and silly premises. The Lucy Show remained on top despite a devastating blow from losing venerable veteran Vivian Vance, whom Lucille Ball failed to talk out of retirement with a sizable salary. NBC's sitcom pallet ran rife with failure as 40% of their sitcoms were handed renewals and rated on the softer side.
Freshman comedies were not the only cancellations ABC and CBS handed out. The Ozzie and Harriet Show, America's then-longest running sitcom, was handed a shameful Saturday timeslot followed by a cancellation notice. Their 14-season record remained intact for 37 years until The Simpsons broke its record in 2003. However, Ozzie and Harriet continues to hold the live-action vs. animation record for an unprecedented 51 years. Next up on longstanding cancellations was Donna Reed with 8 season, also handed the same shameful Saturday package offered to Ozzie and Harriet. The first animated sitcom, The Flintstones, ended after 6 seasons. The Hanna/Barbera production became a Top 20 sensation its first season and would remain in the top 30 until 1963.
McHales's Navy ended after 4 seasons, Patty Duke and The Farmer's Wife after 3, and The Addams Family after 2. All ranked below 60th place. The Addams Family's CBS knockoff, The Munsters, also ended after two seasons, one rank higher than the Addams Family. CBS held more room than ABC to cancel its sitcoms as other longstanding shows left the air. The Dick Van Dyke Show and Hazel ended after 5 seasons, and My Favorite Martian was sent out of the orbit after 3 seasons. Not a single sitcom on NBC's roster possessed more than 2 seasons during the 1965-66 season, and the six cancellations all were freshman, including the ultra-embarrassing My Mother the Car.
Sources
1. http://fbibler.chez.com/tvstats/by_5_yr_period/top_programs_1965-1970.html
2. American Television History, 1967 -- http://americanradiohistory.com/Archive-Television-Magazine/Television-1967-Aug.pdf
3. https://en.wikipedia.org/wiki/1965%E2%80%9366_United_States_network_television_schedule