Background: Sir Walter Winterbottom, CBE (31 March 1913 - 16 February 2002) was the first manager of the England football team (1946-1962) and FA Director of Coaching. He resigned from the FA in 1962 to become General Secretary of the Central Council of Physical Recreation (CCPR) and was appointed as the first Director of the Sports Council in 1965. He was knighted for his services to sport in 1978 when he retired. The Football Association marked the 100th anniversary of Winterbottom's birth by commissioning a bust which was unveiled by Roy Hodgson at St Georges Park on 23 April 2013 in recognition of his outstanding contribution to the development of English football.
Context: Although Winterbottom is best known as the England team manager, it is in coaching that he made important contributions to the development of English football. He made no secret of his belief that his job as Director of Coaching was the more important of his two roles at the FA.  When he joined the FA in 1946, club directors, managers and players were cynical about the need for coaching but Winterbottom had a passion for coaching and a vision of how it should develop. He soon created a national coaching scheme with summer residential courses at Lilleshall, Shropshire, and persuaded some of his international players to take the courses that led to exams for the FA preliminary and full coaching badges. This gave the scheme credibility. They developed their teaching skills by coaching in schools and then moved into part-time coaching positions in junior clubs. He gathered around him a cadre of young FA staff coaches: men like Bill Nicholson, Don Howe, Alan Brown, Ron Greenwood, Dave Sexton, Malcolm Allison, Joe Mercer, Vic Buckingham, Jimmy Hill and Bobby Robson. Over time a new breed of managers emerged in the League clubs and began to change attitudes to coaching.  Winterbottom's courses were expanded to include professional players, referees, school masters, club trainers, schoolboys and youth leaders. In addition to Lilleshall they were held at Loughborough College, Carnegie College, Bisham Abbey and Birmingham University. In 1947 three hundred had taken the full coaching award and the numbers of qualified coaches grew each year.  The courses attracted international participation and praise. Winterbottom was regarded by many as a leading technical thinker and exponent of association football, of his generation, in the world and lectured internationally.  He inspired a new generation of managers, most notably Ron Greenwood and Bobby Robson, who graduated through every level of coaching, both eventually becoming England team manager.
Question: How long were they with the team?. Whats the answer?
graduated through every level of coaching, both eventually becoming England team manager.