I think judging a players ability is very subjective. We must all have had debates with mates over certain players, with one liking a player and one not. I used to have this discussion with a mate over Matt le Tissier all the time. Similarly, on this forum there used to be quite lively debate over the pros and cons of Lee Cattermole- it would be interesting to see the stats on him. I've even seen qualified coaches being miles apart on their assessment of a player. The data helps to remove some of that subjectivity. You still need to watch a player because there are obviously aspects that the data can't capture but it can surely help to give a greater depth of understanding of a players abilities. Its another tool to use, not a breaking down of football to simple numbers.