While getting notes on a pilot script last week, my friends coined a new term I'm going to do my best to get into the screenwriting lexicon: "The Golf Ball."
Basically, this came about because one of the members of my writing group expressed disappointment that my story lacked the complexity of, say, a strong Larry David-developed episode of Curb Your Enthusiasm. He said I had several plot lines set up over the course of the script and he was expecting them all to collide in the end for maximum comic effect. Most of all, he pointed out one element in particular that had been established in an earlier scene, then neglected when it came time to fashion the climax.
"Give us 'the golf ball,'" said another member of the group. It's a measure of how in sync we are that I knew EXACTLY what he was referring to. In a classic episode of Seinfeld called "The Marine Biologist," an early scene reveals Kramer's plans for the day. He's bought a bunch of new Titleist golf balls and he invites Jerry and George to drive out to the beach with him "and hit 'em into the ocean!" The others decline, but Kramer follows through on his plan.
Later in the same episode, George gets embroiled in a lie where he's trying to pass himself off as a marine biologist to a woman he's attempting to date. It's his bad luck that he takes her for a walk on the beach just as whale in distress is discovered. As George and the woman happen upon the scene, one bystander cries out, "Is anyone here a marine biologist?"
Wonderful, now George has to either save the whale (which he has no idea how to do) or blow the lid on his lie (which he REALLY doesn't want to do.) He marches towards the water, and then we fade into George sitting at the diner, telling his friends what he did. It's one of the classic Seinfeld monologues.
George reveals that he was in a position to see that the whale's breathing was being impeded, and so he reached in the blowhole and pulled out the obstruction - a golf ball! A Titleist, to be precise. The detail that the audience has all but forgotten about is revived as the punchline and the cause of the climax. Thus, "The Golf Ball" is my term for the comedic plot device that unites two or more unrelated story threads.
I grant this is similar to an existing screenwriting term: Chekhov's Gun. If one insists on a distinction between the two, I see The Golf Ball being more of a comedic device. That, and I'd bet that more aspiring writers these days are likely quite familiar with Seinfeld, while to them, Chekhov is that Russian guy from Star Trek.