Quantifying truthfulness in films "based on a true story"

With awards season upon us, lots of films "based on a true story" are in contention. It gives films a little emotional boost to say it really happened, but how much of the film is true? David McCandless created a metric to quantify it based on scene-by-scene analysts. So Selma hets a 100%, and The Imitation game gets 41.4%. (more")