Small town club’s Serie B adventure captivated football and inspired a famous book. That spirit remains and is being passed to their successorsThe WhatsApp group flickers into life at about 6am every day. It is the manager who goes first because, when you are 79, old habits die hard. “Good morning,” Osvaldo Jaconi hails his former players and staff before, little by little, the salutations roll in from across Italy. Maybe it is someone’s birthday or another special occasion; the conversation may be accelerated by an in-joke that recalls why, three decades ago, they were brought together in the first place. Just in case anyone could forget, the group’s title says: “Serie B.”This is how miracles stay alive. Perhaps it is the point of what Castel di Sangro achieved in 1995-96. A rag-tag bunch from this backwater in mountainous Abruzzo had risen from local amateur leagues and then, in a crowning triumph with little precedent, made it to the second tier. “It’s like 30 years haven’t passed,”...