Every football fan has had a sneaking suspicion that certain referees give their club a hard time.
That sense of paranoia may be fuelled by things such as the number of cards dispensed by individuals during games, or the awarding of penalties to opposition teams.
Usually it is simply a case of confirmation bias, but Free Super Tips have used a new algorithm to examine which teams are actually favoured by referees.
Using data from the last five seasons - from 2012/13 to 2016/16 - and applying an affinity algorithm that takes cards, fouls and penalties given, they have come up with some interesting conclusions.