I knew Simon Kuper and Stefan Szymanski as the authors of Soccernomics. I just found out they released the same book in the U.K. under the title Why England Lose & other curious football phenomena explained. Below you will find a diagram based on their forecasting formula. Though not perfect science, this is as close to scientific as anyone has ever gotten. Factor in population, GDP, experience, home court advantage and you end up with some interesting and not so surprising results.