League tables are controversial and for good reason. Few things are simple enough to be measured by a single outcome like, for example, the number of exam passes or successful heart operations. But even if we do accept a single yardstick, we haven't yet reckoned with chance, which by itself can produce apparent patterns to delight any tabloid editor.
Emily Poskett works as a government statistician for the Department for International Development. With lots of travel and the opportunity to make a real difference in poorer countries, her job is far more than just number crunching.