Very interesting and technical discussion.
There are a lot of statistical techniques around and very easy to generate all manner of figures and inferences from them. In the medical world it is complicated enough (where cause and effect are better established) but in the sporting world there are other even more complicating factors, such variation due to human behaviour, including irrational behaviour, fashion changes, e.g. Attacking players lining up in a clump at corners then going to different positions, strength of selected players e.g. swansea can be vulnerable in the air if Llorente or Fer are not available but they can be more potent if they are. More important in this context is how players read the trajectory of the ball, and predict where they should go.
Statistical analysis is ok for mathematicians and sports scientists but sometimes you have to go with the evidence of your eye and adapt on the pitch for the peculiar circumstances of the game situation.
This is what allows all of us non-einsteins to play and comment.
