What was the ranking algorithm that is mentioned in the beginning of the movie? Eduardo writes some mathematical expression on the window (I am sure they were made up!).
Actually what ranking strategies could be used in this scenario? I believe a ‘rank’ would have to include multiple parameters. Perhaps something in the lines of svms ?
It's called the Elo Rating System (<a href="http://en.wikipedia.org/wiki/Elo_rating_system" rel="nofollow">http://en.wikipedia.org/wiki/Elo_rating_system</a>).<p>From the article, it's used to rank the relative skill of two players. It was created for chess, but I believe underpins most competitive ranking today including Xbox LIVE.
Also I found interesting that the geek students considered this trivial formula a revelation. Does fall out of the context of the brilliant hacker culture :) When we needed a ranking system several years ago, I came up with this in half an hour, then figured out it already exists, is called Elo, and used everywhere, so we just copied their coefficients.
There was an interesting statistics/modelling competition on Kaggle for different approaches to chess ranking.<p><a href="http://kaggle.com/chess" rel="nofollow">http://kaggle.com/chess</a>