Effect of the 'Crouch, Bind, Set' engagement routine on scrum performance in English Premiership Rugby

The effect of the new scrum engagement sequence introduced at the start of the 2013/2014 season on scrum performance has not been evaluated. This study compared scrum performance indicators pre- (2012/2013 season) and post-law change (2013/2014). Several performance indicators at the scrum were identified in 20 games from each season of the English domestic Premiership. These included the number of penalties, free kicks and resets awarded. A Mann Whitney U test showed a significant increase in the number of scrums per game, from 17.50 to 23.85 (p = 0.003, ES = 0.47). This was contributed to by a 112% increase in the number of reset scrums (p < 0.0005). Of the resets, there was a significant increase in the number of scrums reset due to collapsing, which is of concern for player welfare. However, resets for collapsing accounted for a similar proportion of the total resets pre and post law change at 52% and 53%, respectively, and may be due to the relative novelty of the technique and stringent law enforcement increasing resets. In contrast, there was a decrease in the number of early engagements from 1.65 to 0.40 per match following the law change which is likely beneficial for player welfare.