A fighter can have all the fundamental skills between the ropes perfected, yet still not make it to the very top of the proverbial mountain. Boxing, primarily, is a sport of both physical and mental stamina. The very top fighters in the game have the physical prowess that keeps them going over the full 12 rounds, while they also have the mental toughness that allows them to keep alert even when the rest of their body is weary. One slip and they've lost the bout. Their record is tarnished forever. That's the harshness of realities at the very highest level. Making sure they don't lose concentration for that crucial split second to allow their opponent in for the knockout blow over the course of a career is a near impossible task for any fighter of note. They'll always have a pretender or two eyeing up the sizeable target on their back it's the nature of the beast that makes it the money spinner we simply can't get enough. So to those men with the fundamental skill set, with physical and mental capabilities to boot. Just who are the men that made it through the entirety of their careers with not a single blemish next to their name? Who are those men that made it through their careers with the most impressive undefeated streaks of all time...