The Fed chairman is a skilled political operator and he was careful to focus his testimony on the long term.

ECONOMIST: Urging restraint | The

Mr Greenspan is a skilled political operator: he knows his every utterance is scrutinised for nuances and he would not want to be blamed for publicly undermining the president's economic strategy.

ECONOMIST: More discipline needed | The

Ferguson -- who is seen as a kind of father figure by some of the young players he developed -- has "that ability to reach out to people, " said Bose, but he is also a skilled political operator.

CNN: Alex Ferguson retires as Manchester United manager

Mr Maduro is said to be friendly and jovial and to enjoy socialising, but he is also credited with being a wily operator and a skilled negotiator.

BBC: Profile: Nicolas Maduro