Jürgen Klopp knew next to nothing about data before he arrived at Liverpool but his first meeting with Ian Graham, the physicist credited with helping to recruit the team that won the title, could not have gone better. Graham, the director of research at Liverpool, decided to demonstrate to him how the metric expected goals (xG) worked. He went through Borussia Dortmund’s calamitous 2014-15 season, when Klopp’s team had slumped from being second to Pep Guardiola’s Bayern Munich the previous season to second bottom at Christmas. “Echter Schrott” was the take of the tabloid Bild, which translates as “Absolute Rubbish”.
Graham had a different interpretation, even before Klopp arrived. His data told him Dortmund remained the second-best team in the league. When Klopp signed his Liverpool deal, Graham took him through Dortmund’s eight worst games of the season, demonstrating how unlucky they were.
