Behind every great joke is a story, and for Jo Koy, one of the most memorable stories of his career involves a baseball game, extra innings and his late stepfather. In his Netflix stand-up special, 'Jo Koy: Blue in the Face,' the comedian delivers a viral bit about attending a Los Angeles Dodgers game with Sgt. Fred Harrison, a decorated Army veteran who was battling cancer at the time.

Koy recently walked through the origins of the joke in an episode of Variety's 'Anatomy of a Joke: Spotlight,' presented by Icon Live. In the special, he recalls taking Harrison, a devoted Dodgers fan, to one of the team's games. When the matchup stretched into extra innings, Koy started riffing on his stepfather's exhaustion, landing on the punchline that has since spread widely: 'He served two tours of Vietnam, and he's going to die in a fucking Dodgers game!'

Rather than simply describing the afternoon, Koy throws himself into a full recreation of it. He channels his stepfather's mannerisms and even the sounds of the oxygen tank that had become familiar to him. At one point in the performance, he picks up the microphone's cord and holds it to his nose, imitating the oxygen mask Harrison wore.

'I'm not going to just talk about Fred. I'm going to bring Fred to life, and you're going to see exactly what I saw when I was a kid,' Koy told Variety. 'You're going to come into my world.'

When it comes to building material, Koy said he prefers to let jokes take shape on their own rather than scripting them. He recalled one show in his stepfather's West Virginia hometown where he spent 30 minutes on stage talking about Harrison and reliving the memories they shared.

'I find when you write it [a joke] down, it starts to sound structured,' Koy explained. 'When you do it on stage, it becomes more conversational.'

That approach reflects the comedians Koy has long looked up to, performers who act out encounters and slip into different characters rather than standing still behind the mic. Watching distinct personalities come alive on stage is something he fell in love with early in his career, and he has folded that style into his own work, including the special, which debuted on Netflix in September.

As polished as the Dodgers bit may seem now, Koy said its roots are plain retelling. 'It's not even a joke. It's literally verbatim what happened that day,' he said of the viral moment. 'It started off with me just telling everybody what happened that day and then inserting tiny jokes, I guess you could say.'