premise: How to drink whiskey<br>Pour " two fingers " of whiskey into a rocks or tulip glass. Rocks glasses, the classic whiskey cup, are short, round glasses made for 12-14 oz or liquid. Tulip glasses are curved wide at the bottom and thinner up top, concentrating the smells near your nose, and are used for more high-class whiskey tastings.
hypothesis: Rock glasses are a set size. 
reason: It says they are made for 12-14 oz.