The idea goes that any two people can be linked by as few as six others; that Person A is connected with person G because they know Person B, who knows Person C, who knows Person D, who knows Person E, who knows Person F, who, in turn, knows Person G.
The theory is understandably contested, but anyone looking for anecdotal proof would do well to start in football.
At Crystal Palace alone the breadth and variety of possible connections repeats: Roy Hodgson and Steve Kember grew up in the same building, and Marc Guéhi and Conor Gallagher shared time at Chelsea, Swansea City, Crystal Palace and England.
The list goes on: Patrick van Aanholt is cousins with Leroy Fer, Eberechi Eze was in the same school year as Marc Bola, and, in a really niche twist of fate, Ray Houghton’s brother went to school with James McCarthy’s dad. Who would have guessed?
Another similarly less known connection is that between 90s full-back John Humphrey - who turns 62-years-old today (Tuesday, 31st January 2023) - and Academy sensation Victor Moses.
Humphrey represented Palace 203 times between 1990-95. During his career in SE25 he scored a screamer against Wolves and played a crucial role in Steve Coppell’s most successful squad in club history.
He retired from football altogether aged 40 and went into teaching at Croydon’s Whitgift school with former Chelsea defender Colin Pates and Palace icon Kember. After a few years Humphrey began coaching a teenage Moses.