Statistics
Not to be confused with stats, or character abilities, Statistics is the study of the collection, organization, analysis, interpretation, and presentation of data. Most people -- fa/tg/uys included -- are terrible at statistics because they are terrible at probability, despite participating in a hobby where random events are very prominent. This can be explained by having a long tradition of dice mojo, believing in the heart of the cards ("topdecking"), and assigning disproportionate importance to a natural 20.