Maybe they'll go against Napoleon, but either way, this seems like a skewed sample. Put the names of all the students in a hat and draw 50 names. Ask those students whose names are drawn. Well, this seems like a nice random sample that could be nicely representative of the entire population. Ask all students whose names begin with N or B. Well, this could be perceived as kind of random, but notice N is the same starting letter as Napoleon. B is the same starting letter as Blair.