Throughout Saturday Night Live's history, the show's cast has been mostly culled from four places: the stand-up world, L.A.'s Groundlings Theatre, the Upright Citizens Brigade Theatres in L.A. and New York, and the Chicago improv sketch/scene (the Second City, iO, and Annoyance theaters). Sure, there are wildcard hires who avoided these standard comedy training grounds, like Fred Armisen – a drummer for a punk rock bank who caught the eye of Bob Odenkirk after making some videos of himself bothering strangers at a music festival – or Anthony Michael Hall – an actor from John Hughes's Brat Pack who had a one-season run on the show in the '80s – or Andy Samberg – who got his start making viral videos for Channel 101. But despite the occasional odd SNL beginnings story, the bulk of the cast throughout the years has come from the aforementioned four places.
Since 1975, there have been peaks and valleys to each comedy theater's influence on the show. In the '80s and '90s, a large portion of the cast were stand-ups, whereas there's only one stand-up on the show now, which currently has more alumni from Chicago's Second City and iO theaters than from anywhere else. Here's a breakdown of what portion of each SNL cast, separated by era, comes from Groundlings, Second City/iO, UCB, stand-up, or that wacky miscellaneous category: