First, Break All the Rules: What the World's Greatest Managers Do Differently ↑
11.20.1.1 Guiding the good towards the great
Counterintuitively, employees already performing above average have the greatest room for growth. Great managers also know that it is hard work helping a talented person hone his talents. If a manager is preoccupied by the burden of transforming strugglers into survivors by helping them squeak above average, he will have little time left over for the truly difficult work of guiding the good towards the great.
Next: Burgess, Mark