Floyd Mayweather and Wladimir Klitschko haven't had a close fight in years. And the chances are pretty good that both men will retire without seeing another one.
In boxing, nothing is guaranteed at the championship level. An extremely determined opponent with a perfectly executed game plan, on a good night, can can force a war on almost any champ.
But of all of the champions in all of the sport's weight classes, the No. 1 dogs in these seven divisions are least likely to get their bones taken away.