Season 1 NBC , 1965 - 1966 Season 2 NBC , 1966 - 1967 Season 3 NBC , 1967 - 1968 Season 4 NBC , 1967 - 1969 Season 5 NBC , 1967 - 1970 Season 6 NBC , 1970 - 1971 Season 7 NBC , 1966 - 1972 Season 8 NBC , 1968 - 1973 Season 9 NBC , 1973 - 1974