NFL fans and ESPN reporters overly optimistic about team prospects

US fans of the National Football League (NFL) and sports reporters assigned to specific teams have unrealistic expectations about how well their team will perform, finds new research from UCL and Oxford University. The study, published in PLOS ONE, also reveals which teams are most liked and disliked, as well as which teams have the most optimistic fans. The main results are from an April 2015 survey of 1,116 US-based NFL fans, who were asked to predict how many games their favourite and least favourite teams would win in the 2015 season. As each team plays 16 games and only one team can win each game, the overall average number of wins across all teams will always be eight. However, the average number of wins across all favoured teams as predicted by fans was 9.59, showing that they were all overly optimistic and cannot all be right. The ESPN data comes from an article published before the start of the 2014 season, in which an expert reporter was assigned to each of the 32 teams and asked to predict how many games that team would win. The experts were all optimistic about their assigned team's chances, with a collective predicted average of approximately one more win than is possible (8.