In 1999, after a series of wildly adventurous jobs around the world, Sam Sheridan found himself in Australia, loaded with cash and intent on not working until he d spent it all. It occurred to him that, without distractions, he could finally indulge a long-dormant obsession: fighting. Within a year, he was in Bangkok training with the greatest fighter in muay Thai (Thai kickboxing) history and stepping through the ropes for a professional bout. That one fight wasn t enough. Sheridan set out to test himself on an epic journey into how and why we fight, facing Olympic boxers, Brazilian...