Adi and Rudi Dassler made sports shoes together - until a feud erupted between them. They set up competing companies, Adidas and Puma, and their bitter rivalry divided the sporting world, their family and even the inhabitants of their home town. 

The Dassler clan turned bickering into an art form - even drawing the likes of soccer legend Pele into their dispute. But did the brilliant fires of hatred produce two world-class companies, or was it a needless distraction from the Dasslers' love for their craft?    

For a full list of sources, see the show notes at timharford.com.