The best example is probably the Marine Biologist episode. You could have never predicted that there would be any connection between golf balls and whales.
I think this was mostly Larry David's work. Jason Alexander once mentioned in an interview that after David left, this "dovetailing" of story lines kind of stopped, and I tend to agree. David continued it (even more pronounced) in "Curb Your Enthusiasm". Even the golf ball twist was kind of repeated - in extreme form and with a baseball - in "Curb".
Side note: another early TV show that often pulled this off to great effect was "The Honeymooners". I think this is the show that had the most influence on Seinfeld. Ed Norton is basically Kramer, Ralph Kramden is basically George, Alice is Elaine, and Alice's mother is Newman (you can also map "The Honeymooners" characters, and even entire plot lines, to "The Flintstones", but that is another story, and AFAIK Jacky Gleason, the creator of "The Honeymooners", considered suing Hanna-Barbera in the 60ies).
Jerry Seinfeld himself once said that we should wait and see if "Seinfeld" is still funny in 50 years like "The Honeymooners" (that was 20 years ago).
"Fawlty Towers" also did this very well.
Whether that says more about me or the show I do not know
"I’d like to say it worked organically or it worked from going backwards, but it worked and didn’t work in all of those ways. It never really happened the same way twice. A couple of times, I would think that I had it down pat, like in the episode with Teri Hatcher, “The Implant.” I had stories, but I also started off with four or five really great scenes. They had nothing to do with each other, but I knew they would make great scenes, so I started finding a way of mating them together. That episode came out great, so I thought that that was the way I would always do it. It never worked that way again. The process of that was pretty much a struggle every time."
https://www.vulture.com/2014/07/classic-seinfeld-episodes-wr...
On reading The Contest:
"David: As soon as the read-through started, the laughs were huge. Big, satisfying laughs. I would glance at [the executives’] faces and they seemed to be enjoying it. You could sense it was a very special show. Then we all walked back to our office afterwards and I think one or two NBC executives were there and they had nothing. They just said, “Very funny.” And I was shocked.
Littlefield: They read it and it was hilarious. And Rick, as an executive for NBC, knew, “Uh-oh, shit’s going to hit the fan.” The broadcast standards executive who was there, was like, “What the fuck?” And Rick was like, “I didn’t know!”
https://www.vulture.com/2017/10/seinfeld-the-contest-oral-hi...
Sometimes what a project like a sitcom or a business needs is rather someone or several members who don't fit in. Because otherwise you start to suffer from creative and intellectual incest.