  Traditionally, most of football statistical and media coverage has been
focused almost exclusively on goals and (ocassionally) shots. However, most of
the duration of a football game is spent away from the boxes, passing the ball
around. The way teams pass the ball around is the most characteristic
measurement of what a team's "unique style" is.
  In the present work we analyse passing sequences at the player level, using
the different passing frequencies as a "digital fingerprint" of a player's
style. The resulting numbers provide an adequate feature set which can be used
in order to construct a measure of similarity between players. Armed with such
a similarity tool, one can try to answer the question: Who might possibly
replace Xavi at FC Barcelona?
