Reproducing the Elo rating algorithm in Ruby is a little challenge that I took upon myself recently for a small hack. The same Elo rating system that was scrawled upon the glass in "The Social Network" as the algorithm that Mark Zuckerberg used on rank people on FaceMash. As an exercise, here's a pass at it with a little BDD thrown in for good measure. A new file - elo.rb: require 'minitest/spec'require 'minitest/autorun'describe "result" do describe "when both players start with rating of 100 ...