Short of an idea for a charity football match? How about playing a black team against a white team? And this is colour of skin I’m talking about, not colour of kits.

Believe it or not, such a match actually took place, in front of a paying crowd, at West Bromwich Albion in 1979. Telling people this has elicited two reactions: first disbelief, and then outrage. How could such a thing have happened? What kind of world were we living in at the time? Well, I’ve been reminded in making this film what a brutal place the world was, especially if you happened to be a black footballer.