"In the earliest days of cinema, little information was available. Audiences just talked about how well the actor was able to convey what was happening in the story with few subtitles and no sound. “Was he a good actor?” was another way of asking “Did the movie make sense?” The names of the performers were inconsequential. Soon, however, audiences began to construct a sort of makeshift continuity between pictures: The girl in that film, for example, is the same actor as the girl in that other film. To ascribe some sort of coherence, fans began writing to studios, requesting the names of the “players,” as they were then called."
—The Hairpin's own Anne Helen Petersen, explaining the rules of the game (as it was in the beginning, and as it is now, and perhaps as it ever shall be).