NHS chief executive and chief executive of the shadow NHS Commissioning Board (2010 ranking: 4)

The first HSJ power list was published in 2006, Sir David Nicholson - newly installed as NHS chief executive - was placed third. The following year he had taken the top slot for the first time. In 2008, Lord Darzi was deemed most influential, with Sir David down one place.

However in 2009, he swapped places with the surgeon-cumminister. Last year, he had slid down to fourth with grim rumours circulating that he and new number one, health secretary Andrew Lansley, were on borrowed time.

In 2011 Sir David has achieved the astonishing feat of regaining the position as the most influential person in health for the third time. His influence over the past six years has outstripped all others. Only Andrew Lansley is in the same ball park - and, while the health secretary is struggling, Sir David is once again on the up.

Sir David owes his primacy to one factor above all: he is a good man for a crisis. As the reforms began to run into trouble in the autumn of 2010 and the scale of the financial challenge became clear to Downing Street - the call went up for a safe pair of hands. Sir David, who was seriously thinking about moving on, was as surprised as any when he was suddenly transformed from the manifestation of the bad old days of top-down command and control to the man who would lead the NHS into the bright, clinically led future.

He has been riding the twin horses of NHS chief executive and chief executive designate of the commissioning board for a year, simultaneously representing the present and the future of the service - a position of almost unprecedented power. He has taken an unforgiving approach to winding down the PCT/SHA system, mirrored by a robust approach to building a new commissioning structure with a tough authorisation regime and comprehensive performance management mechanisms and support functions. He will eventually wave goodbye to responsibility for the provider sector, but is doing his best to whip it into financial sustainability before he does so.

The expected criticisms are already coming his way: notably that he plans to centralise power, leaving clinical commissioning groups little freedom. Sir David would no doubt counter that they can have all the freedom they want, as long as they can demonstrate they are spending public money wisely and securely. Creating an organisation which satisfies his desire for “grip” on the system, while not seeming (too much) of an ogre to emergent clinical commissioning groups will be his biggest challenge. After that will come negotiating the first DH mandate - setting out the outcomes the government wants the board to oversee - and agreeing a shared vision with Monitor in its new sector regulator role. Sir David will also have to build a relationship with board chair Malcolm Grant.

Sir David begins 2012 as the master of all he surveys. But his power will attract increasing scrutiny and the trouble with being a safe pair of hands is that any slips are judged that much more harshly.