Serial (radio and television) usually ran from Monday through Friday at exactly the same time every day. A show called The Smith Family which ran only one night a week on WENR in Chicago during the early 1930s was credited as the "great-granddaddy of the soap operas" by radio historian Francis Chase, Jr. One of the other shows that helped pioneer the daytime soap opera/serial was "The Guiding Light", which debuted on NBC radio in 1937, and then switched to CBS Television in 1952. "The Guiding Light" final episode aired on September 18, 2009, having a total of 15,762 episodes air on CBS. Some
Soap opera story was completely resolved by the end of the episode, and there were no end-of-episode cliffhangers. After the first couple of seasons, all three shows changed their story format to that of a pure soap opera, with interwoven ongoing narratives that ran over several episodes. "Dynasty" featured this format throughout its run. The soap opera's distinctive open plot structure and complex continuity was increasingly incorporated into American primetime television programs of the period. The first significant drama series to do this was "Hill Street Blues". This series, produced by Steven Bochco, featured many elements borrowed from soap operas, such as