Re-examination of Importance of Kick-off and 50m Restart Kick Play in Rugby Football Games

Abstract

The purpose of this study was to re-examine importance of kick-off and 50m restart kick (KO) play in rugby football games with their changes in recent years to be considered. Twenty top-ranking, high level international matches in 2004-05 were analyzed, and data from an earlier study on thirteen matches at the same level in 1994-95 were utilized and supplemented with additional analysis. The main results were as follows: 1) The number of KO plays in 2004-05 was not significantly different from those in 1994-95. However, the ratio of KO plays in the total number of set plays increased significantly. 2) Short KO (S-KO) plays in which kicked ball falls between the 10m∼22m lines and long KO (L-KO) plays in which kicked ball goes beyond the 22m line were executed at an approximately even rate in 2004-05 although almost all KO plays were S-KO in 1994-95. 3) The average rate of ball acquisition by kicking sides in S-KO in 2004-05 was .32 even in total. The value was still low and was not significantly different from those in 1994-95. 4) Whether the ball could be gained in S-KO was significantly related to the time during which kicking sides occupied the opponent's territory beyond their 10m line continuously and the rate of scoring after KO in 2004-05 as well as in 1994-95. 5) Whether the ball could be recaptured by kicking sides while occupying the opponent's territory beyond their 10m line continuously after L-KO was significantly tied to the territory time and the scoring rate in 2004-05. It was confirmed from these results that KO play still played an important role in rugby football games in recent years.