The improv-troupe-to-SNL pipeline is well-known. Whether it’s the Upright Citizens Brigade (UCB) theatres in Los Angeles and New York, LA’s Groundlings theatre, or Chicago’s Second City theater, Lorne Michaels and co. have sourced talent from the best improv groups in the US for decades, often putting potential SNL performers through brutal audition processes. But that doesn’t necessarily mean they’re looking for those improv skills to be put to use on the show itself.

Speaking to Vulture, the showrunner, who’s overseen SNL since it debuted in 1975 (bar a brief hiatus in the ’80s), explained how improv can actually make things difficult for a show that relies on everything being finely-tuned:

“There’s a lot of training — UCB and all of that — and it’s very good training. But what we do here is so nailed down that there’s very little improvisation. Every line, every bit of dialogue, has a camera cut attached to it. If you’re not where you’re supposed to be, then they’re going to miss the shot.”

Plenty of cast members have run afoul of Michaels and his show’s strict requirements. Interestingly enough, it was a performer known more for standup than his improv abilities that was infamously let go after deciding to put his own spontaneous spin on a live sketch. Damon Wayans joined the SNL cast in season 11 all the way back in 1985, but was fired the following year after he decided to play a police officer as a stereotypically flamboyant gay man at the last minute. Wayans, who had grown increasingly frustrated with his experience on the show and knew exactly what he was doing, said after the fact, via GQ, “I knew I was going to get fired for it. Lorne did the right thing.”