Home advantage, rivalry, and referee bias in representative rugby
Purpose - The purpose of this paper is to examine whether home advantage (HA), wherein a team is more likely to win, and by a larger margin, when they are playing at home vs away, exists in representative rugby competitions involving teams comprised of "all-star" players from several clubs. It also assesses whether referees are biased in favour of the home team, and whether this is the cause of HA.
Design/methodology/approach - A complete consensus of matches from the State of Origin Rugby League and Tri Nations Rugby Union competitions were analysed via hierarchical regression models estimating parameters for favourite/underdog status of teams, general home/away status, team-specific home/away status, and rivalry-specific home/away status.
Findings- Significant HA exists in both competitions, and within Tri Nations, the size of the effect varies by team and specific opponent (i.e. rivalry effects). Although there is evidence of referee bias in favour of the home team, the penalty differential between the home and away teams does not mediate HA.
Originality/value - This is the first study examining HA in representative rugby league, and shows a statistically significant effect. Further, the results reported here refute an earlier investigation of the Tri Nations competition, which found little or no evidence of HA. By including a complete census of all matches rather than a small sample, this research finds a statistically significant HA effect, which varies by team and by specific rivalry.