The Superfight: it’s a term used so often these days that it’s become a novelty. In theory, it identifies a bout that is designed to bring two fantastic fighters together in a clash that speaks to the best aspects of their relative skills and styles. In boxing, it has often been used to identify bouts that could never happen: Muhammad Ali versus Mike Tyson, Sugar Ray Robinson versus Floyd Mayweather Jr., Roberto Duran versus Manny Pacquiao. But in the sport of MMA, it is used to describe the...