Managers with proven track records are often recruited to the top Premiership clubs from other leagues all over the world. Mourinho, Wenger, Ancelotti, Pellegrini and a host of others were given top jobs without having managed lesser Premiership clubs. Others debut in the Premiership with their promoted clubs. Yet it’s equally often a case of the devil you know. In any one season, about 73% of managers have managed in the Premiership before. Such managers are known quantities, safe hands who frequently move between clubs. and in this post I visualize this manager traffic to see if there are any patterns.
To qualify as having “managed” a club, a manager must have been in charge for at least 20 games, so I’m excluding brief caretaker stints. The diagram below shows the Premiership manager traffic from the period of its inception, up to the end of the 2015 season.
Premiership Manager Traffic 1992-2015
In the network I’ve drawn, the size of the circle is determined by the number of Premiership managers the club has had, and the lines link pairs of clubs that have shared a manager. So Manchester United and Everton are linked because David Moyes managed both clubs, while Chelsea and Portsmouth are linked because of Avram Grant. Thicker lines mean that a pair of clubs have shared more than one manager. For example Hoddle, Redknapp and Pochettino have all managed Southampton and Spurs.
The colours are selected by applying an algorithm that detects sub-networks or communities within the overall structure. Some of them are quite interesting.
There is clearly a Southern network taking in the South coast and London, that includes Chelsea, Spurs, Southampton, Portsmouth, West Ham, Charlton and QPR. Then there is a sort of Central/M1 group covering the spine of the country which consists of Midlands clubs like Villa, Coventry, Leicester, and Nottingham Forest, extending north up the M1 to Sheffield United and Sheffield Wednesday and Barnsley, and south down the M1 to Watford.
The other communities are less geographically cohesive, but the relationship between Newcastle, Blackburn and Liverpool looks a bit incestuous. In fact, two managers, Kenny Dalglish and Graeme Souness have managed all three of these clubs, while Sam Allardyce and Roy Hodgson have managed two each (Blackburn / Newcastle and Blackburn / Liverpool respectively). I haven’t done a simulation, so I don’t know whether this can be put down to chance or not. My instinct says the connection isn’t random.