Deontay Wilder and Gary Russell Jr. have both shown the kind of explosive power that thrills fans. But both undefeated rising stars have frustrated boxing fans, as well, due to their reluctance to step up the level of their competition.
Developing a boxing star is a tricky process. If a fighter's team matches him too tough too soon, catastrophe can result.
On the other hand, fans begin to grow impatient when an obviously talented prospect spends too much time fighting trial horses and second-tier journeymen.
Some of the fighters on this list will be among the biggest stars in the sport in the years ahead. But they all need tougher competition to reach their fullest potential.