Nothing to do with the TV show of the same name, "Mastermind" was actually an infuriating puzzle game where you had to crack the code by matching four different coloured plastic pins set in a brown plastic board.
First sold in 1972, its commercial success can probably be traced to the picture of the alluring young woman and wise old sage on the box - in reality a hairdresser from Leicester called Bill Woodward.
It had nothing to do with the game, of course, but seemed to promise: "Yes, winning this game will gain you the respect and love of this beautiful girl, and prove your wisdom to all - honest".
It was The Game of the Year in 1973 and has since spawned a whole family of variations - including Number Mastermind, Mini-Mastermind, Electronic Mastermind, Walt Disney Mastermind, Travel Mastermind, and the sumptuous after-dinner Royale Mastermind.
Celebrity fans of the game include Joan Collins and Omar Sharif.
Bill Woodward, whose face has found its way inside 35 million sideboards, was paid a one-off modest fee for his photo.