Arsenal are the most inconsistent team I have see In recent year in the English premier league. Arsenal has been rivalling Manchester city for the English premier league for some years now, this is the season where Manchester city aren't at their best giving then an opportunity at the trophy but they are now bottling the league to Liverpool.
In my opinion, Arsenal's only weakness is that they don't have a champion mentality. Just look at the last few years, they have always given tough competition to Man City, even Arsenal was once the longest leader of the standings but failed to become champions. Now Arsenal's classic illness has recurred, as Man City slipped due to their declining performance, Arsenal were unable to take over the top of the standings from Liverpool.