One of the surprises of the American presidential election was the attacks from the Republican side. Not that they were attacking Obama (hey, unless the airwaves were full of attack ads from both sides, how would we know there was an election on?), but rather that they were attacking a statistician, Nate Silver. But Mr Silver is having the last laugh now, having predicted every state correctly even as most media were saying that the race was tied (or that it may possibly be drifting ever so slightly in Obama's favour). But how did Mr Silver predict the presidential race so accurately? What was this dark magic that he used?