The FIFA15 database has detailed ratings for 11,350 players, including lesser known names like Dominic Knowles and Ciaran O'Connor. The dataset not only has data on overall effectiveness, for instance Ronaldo and Messi had the highest overall scores, but also on individual skills. These include technical skills like passing, shooting, dribbling, and defending, as well as overall fitness attributes like pacing (sprint speed and acceleration) and physical ability (strength, stamina, and jumping).
Using the dataset, I examined the extent to which these abilities were associated with overall effectiveness. However, the skill ratings can't be compared to one another - what does a one-point increase in passing vs a one-point increase in shooting mean?
Hence, the variables were first normalised, meaning instead of the raw score, they measure what it means to be better relative to the next guy (of sorts). The results in the charts below tell us how becoming better than the next guy in shooting helps you become better than the next guy in overall effectiveness, relative to becoming better than the next guy in dribbling. This makes the traits more comparable (but don't bother reading the y-axes below).
The results are quite intuitive. The most important skill for defenders is "defending", which refers to traits like marking and tackling. Defending far outweighs all other skills, so defenders ought to have focused training sessions.
Next up are the midfielders. A good midfielder is one with a good combination of two skills - passing and dribbling - as they need to bring the ball up from a defensive to an offensive position.
Last are the forwards. No surprises again, as shooting comes up tops, with dribbling second.
Hence, the analysis of FIFA15 player ratings has thrown up rather obvious findings - a good defender is one who is good at defending (duh), a good midfielder is one who is good at dribbling and passing, and good forwards dribble and shoot well.
One interesting finding, however, is that traits related to overall fitness - pacing and physical - don't seem to be important across all positions. Perhaps skipping a few fitness sessions won't hurt footballers too much.