The idea for the show began as a movie about "a mob boss in therapy whose mother was his enemy," but instead it became one of the most successful series in the history of cable TV, The Washington Post said Saturday.

The show brought new attention to Time Warner's premium cable channel, Home Box Office. A spokesman for HBO said research shows the audience for "The Sopranos" includes "the intelligentsia" as well as action fans.

When asked when he finally decided how the show would, Chase said: "It has all been planned out, we always knew exactly where it was going, but within that framework, we left a lot of room for each episode to have its own character and to invent stories that would fit in with the continuing story -- if that makes any sense."

The final episode is set to air Sunday night.