This graphic represents Chelsea's formation in a home match against Manchester United. 

Each circle (node) represents a player. The centre of the circle is the player's average position on the ball, and the size is proportional to his "betweeness". Players having high betweeness are influential because they control the  connections to other players in the team. Take these players out of the game and you destroy the team’s ability to play.

The lines between the nodes show successful passes between players with the thickness of the lines proportional to the number of passes. The direction of the passes is represented by the curvature of the lines. The target node (player to) is clockwise from the source node (player from)

The different coloured nodes represent different “passing communities”. The players in a passing community pass more often to players in the same community and less often to players in other communities.  The communities thus represent combinations of players who work together on the pitch.

This type of diagram can help coaches understand patterns of play and partnerships within the team.