How much impact do individual players have on their team's performances?

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The chart above details something of the relative contribution made by individual English Premiership players to their team performances: it maps the amount of goals scored and conceded per ninety minutes with each player on the field this season.  In effect, this chart mimics the plus/minus stat used in hockey*, adjusted for time spent on the field.

The sample size is relatively small – teams from five teams were included, one from each of five categories: last year’s champions, Manchester United, a top-four contender in Tottenham Hotspur, two suspiciously mid-table teams in Aston Villa and Southampton and promoted Cardiff City. 

A player’s contribution can be surmised from how far he is from a large cluster of teammates – these represent the players a manager thinks of as the core of his team.  Examples are easily found in the defensive units of Spurs, Villa, Southampton and Cardiff. 

The spread also represents the amount of squad rotation favoured by certain managers – the northwest regions of the graphic indicate Manchester United have a core that manager David Moyes is currently coming to grips with simply by virtue of the player spread.  Southampton, however, are far more congested.

We can see that the player who represents the greatest forward boon to his side is Wayne Rooney, who after a slow start, has made a startling return to form at Old Trafford.  While it’s no surprise given his team’s relative miserliness, Nathaniel Clyne of Southampton seems to have proven the difference between the Saints scoring or not.

(This ongoing project began as an attempt to keep plus minus records for individual Premier League players; you can find the results here: so far, the player with the worst plus/minus ratio is Kim Bo Kyung of Cardiff City followed by Ashley Young of Manchester United; the player from the five teams selected with the best plus/minus stat is again Nathaniel Clyne).