On Separating individual from organizational mediocrity.
Recognize the difference between organizational mediocrity and individual achievement. Highly effective individual may become ineffective when

• Skills are not matched to the task, the task too large or conversely too small for the employee.
• Incentives are matched to unstated objectives rather than formal objectives.
• Highly skilled individuals may be perceived as mediocre when routinely given high risk assignments.. An example is the ob/gyn who had a high complication rate. In reality she was highly effective and was one of few willing to accept the most difficult ob cases.

In conclusion the manager has many tools at his or her disposal. I highly reccomend implementing the Law of Three. The Marine core had it right when it exercised the command of three. Three platoons to a company, three companies to… When you have made the decision to let mediocrity go, consider focusing on the two or three things that one-year from now will made a difference.