You’d need to make the referees blind to which team’s stadium was home. My best shot: blindfold the referees, put them in cars, drive them to random stadiums (

You’d need to make the referees blind to which team’s stadium was home. My best shot: blindfold the referees, put them in cars, drive them to random stadiums (of teams they have never refereed and have never seen the inside of - so preferably in a different country)*, put noise-cancelling headphones on them and dress all fans in white shirts. * or use a different stadium but fill it with more home than away supporters? But then perhaps the home effect relies on it being the home stadium.