This is a rewrite of ecto / mugshot-wars using MongoDB instead of Reddis and Jade templates instead of EJS. The script uses the elo rating algorithm to compute relative value of comparison. The original version of the type of app goes back to Mark Zuckerberg's Facemash which was the predecessor to Facebook.
According to The Harvard Crimson, Facemash "used photos compiled from the online facebooks of nine Houses, placing two next to each other at a time and asking users to choose the 'hotter' person".