1966 was a huge transition year for the NFL because it was the first season of the Super Bowl to decide who was the pro football champion of America, not the world. The championship game between the Green Bay Packers of what eventually became the National Football Conference and the American Football Conference. It was the first year of divisional play in the NFL where the Eastern Conference and Western Conference was broken up into four team divisions. Pre-1966 the NFL Championship was played between the Easter and Western Conference’s regular season champions. No playoff games at all before the Championship, unless their were ties for first place in the conference’s. Big year for the NFL because they won the first Super Bowl and was at the beginning of the end of the NFL-AFL rivalry as they became of league by 1970 with the NFC and AFC. So the NFL was certainly in transition in 1966-67 and becoming a much larger national league.