[D4N_]

Whilst I agree that many self-help books are poor, I think it's unfair to dismiss someone as a coach simply because they never achieved greatness. There are many examples of successful sports people who's coaching achievements far exceed their achievements as a player (Sir Alex Ferguson, Jose Mourinho or Arsene Wenger are all good examples). This is because the skills required to coach are different (although overlapping) with the skills necessary to be an elite athlete.