What's behind the success of certain professional soccer clubs? Is it money, luck, skill? The answer may surprise you..

The use of analytics in sport is now well embedded. 'Marginal gains', the bedrock upon which the cycling coach Dave Brailsford built his greatest successes are cornerstones of most sports nowadays. But, until recently, that did not apply to the biggest sport in the world. Not in soccer. It was as though this simplest of sports is too complicated for statistics. Or that only one statistic counts, the number of times the ball hits the back of the net. ‘The only statistic that counts,’ there’s an often used and annoying stock term.

However, in the last 10 years, professional soccer clubs of all levels of wealth and stature have bought into analytics. Data analysts are now a major part of every top professional club. They interact with players, advise coaches, examine the strengths and weaknesses of teams, establish likely tactical organization of different sides; even focus on what a referee might allow and penalize.