Arsenal finally ended a 22-year wait to win the Premier League title last season but history shows that successfully defending it is a rare achievement, leaving manager Mikel Arteta with the unenviable task of turning a breakthrough into a habit.
Only three managers -- Alex Ferguson, Jose Mourinho and Pep Guardiola -- have retained the Premier League crown, a reminder that England's cut-throat top flight has a habit of consuming champions almost as quickly as it celebrates them.