It's the idea that any two given people in the world, no matter how far apart or unrelated, are connected through six people or less. I forget whether it's been proved or disproved yet.

[ Sometimes it feels like Recollé is such a small world, they'd only need two or three degrees, especially given the Retrospec app connecting so many of them at once. He used to think it was a good thing. ]

...I didn't think of it either, but you're right. Multiple leaders would be harder to hide from Retrospec... In prominence, they'll be cut off from the app. There doesn't seem like a way to win.