The English Premier League is blessed with some of the very best managers in world football.
But time and time again, clubs make poor decisions, appointing so-called "messiahs" that end up doing more damage than good during their tenure.
Whether it's poor transfer targets, wild spending or just a distinct lack of positive results, these men keep finding jobs despite the warning signs being glaringly obvious.
While Sir Alex Ferguson and Arsene Wenger keep raising the bar, the likes of Martin O'Neil and Sam Allardyce continue to be given second and third chances to prove their worth.
Although some of these managers are not currently active, all four continue to be linked with new posts in the near future—more fool the chairmen that employ them.
Here are the leading contenders who should come with a toxic warning...