Football is a game of light and shadow - a team attracting their opponents to one side of the pitch so they can then attack their blind side, the body swerve to get past your marker without even touching the ball, a side conceding the lion's share of possession so they can then pounce on their rivals' disorganised lines.
The human mind is much better equipped to notice and understand what happens, rather than what does not happen. Sir Alex Ferguson, for instance, chose to sell Jaap Stam because the statistics that he had at his disposal told him that the Dutch mainstay was not tackling as much. Only much later did it dawn on the Scot that Stam's positioning was improving in such a way that he didn't need to tackle as much.
In the world of the blinding lights provided by the stratospheric numbers of Cristiano Ronaldo or Lionel Messi, or the showstopping saves and long passes of Manuel Neuer, it is sometimes hard to discern what goes on behind the curtain. In other words, apart from club or personal preferences, what makes a full-back or a midfielder better or worse than their team-mates or competitors?
Case in point, Liverpool's fortunes changed for the better over the past few weeks, coinciding with holding midfielder Lucas Leiva's return to the fold. Was it a mere correlation or, on the contrary, cause and effect? The Brazilian, always so discreet and effective, can often fly by under most spectators' radar, but his two displays against Chelsea for the Capital One Cup are indeed on of the best records of just what the mission of a player in his position is.
In the video below, Lucas hardly ever seems to do anything of significance - but instead of searching for the light, try to imagine what would happen if he hadn't been around to stifle one threat here, to distribute the ball nicely there, or just taking up the space that would have allowed the opposing forward to thrive. By doing that, one might realise that some things will not remain unseen ever again.