“These young guys are playing checkers. I'm out there playing chess.”

2010s, 2015, Interview with Jim Gray (September 2015)

Quoted by Hippolytus, Refutation of all heresies, IX, 9, 4 (Fragment 52), as translated in Reality (1994), by Carl Avren Levenson and Jonathan Westphal, p. 10
Variants:
History is a child building a sand-castle by the sea, and that child is the whole majesty of man’s power in the world.
As quoted in Contemporary Literature in Translation (1976), p. 21
A lifetime is a child playing, playing checkers; the kingdom belongs to a child.
As quoted in The Beginning of All Wisdom: Timeless Advice from the Ancient Greeks (2003) by Steven Stavropoulos, p. 95
Time is a game played beautifully by children.
As quoted in Fragments (2001) translated by Brooks Haxton
Lifetime is a child at play, moving pieces in a game. Kingship belongs to the child.
As quoted in The Art and Thought of Heraclitus (1979) translated by Charles H. Kahn

Source: L'Allegro (1631), Line 94

Source: Smiles to Go

page 170
Your Job-Hunt Ltd – Advice from an Award-Winning Asian Headhunter (2003), Successful Recruitment in a Week (2012) https://books.google.ae/books?idp24GkAsgjGEC&printsecfrontcover&dqnigel+cumberland&hlen&saX&ved0ahUKEwjF75Xw0IHNAhULLcAKHazACBMQ6AEIGjAA#vonepage&qnigel%20cumberland&ffalse, Managing Teams in a Week (2013) https://books.google.ae/books?idqZjO9_ov74EC&printsecfrontcover&dqnigel+cumberland&hlen&saX&ved0ahUKEwjF75Xw0IHNAhULLcAKHazACBMQ6AEIIDAB#vonepage&qnigel%20cumberland&ffalse, Secrets of Success at Work – 50 techniques to excel (2014) https://books.google.ae/books?id4S7vAgAAQBAJ&printsecfrontcover&dqnigel+cumberland&hlen&saX&ved0ahUKEwjF75Xw0IHNAhULLcAKHazACBMQ6AEIJjAC#vonepage&qnigel%20cumberland&ffalse
Context: Good decision-making is like playing chess and you must avoid making hasty decisions without thinking of how that particular decision will impact on different aspects of your work and organization. The worst kind of decision-making is to decide to delay a difficult decision until later or to pass it to someone else to have to make. You will never excel and be valued by your colleagues if you get into these habits of procrastination and passing responsibility to others.

“Because it is the only thing in the world where I can see all the factors and understand all the rules.”
They (p. 55)
Short fiction, Off the Main Sequence (2005)

Source: Michaelmas (1977), Chapter 7 (p. 98)

Speech given during the 1988 Barrick Lecture Series at the University of Nevada, Las Vegas

As quoted in "The Bright Side of Chess" (1952) by Irving Chernev, p. 107