The Friday File: Back in the heyday of TV 1955-2000, when there were growing numbers of local TV affiliates, the average TV series lasted two years and had about 20 episodes/year. With the rise of streaming and away from syndication, exclusivity, novelty, and binge-ability are paramount rather than consistency and broad popularity. Not surprisingly the average series is now one year long, and the number of episodes/year is just 10.