Gennady Golovkin and Sergey Kovalev were two of boxing's biggest breakout stars in 2013. Each man cut down four opponents by brutal stoppage this year, earning them ever-growing legions of fans in North America.
I don't expect to see either man lose in 2014.
In most cases, once a fighter breaks out to the next level, it only gets harder for him to keep winning. But one thing all six fighters on this list have in common is that they have seemed to improve as their competition has gotten tougher.
That's often the mark of a fighter who will be able to remain unbeaten for a long time.