A writer and tennis player seeks insights and inspiration by traveling across Switzerland in the footsteps of Roger Federer. Roger Federer could live anywhere in the world, but he always returns to the place he loves most: Switzerland. Dave Seminara is a mad traveler and tennis lifer who has written about Federer for The New York Times and other publications. A pair of autoimmune diseases and a knee surgery kept Dave from playing tennis for years, but as he inched toward recovery, he had a bright idea: why not start his tennis comeback on hallowed ground—courts that his hero Roger Federer...