Abstract
The purpose of the study was to examine the relationship between performance in the tackle situation in rugby union and the factors that make a play successful, and to gain useful insights for non-top-level through a comparison of the world top level and the university level in Japan. The main results of this study were as follows; 1）Tackling the upper body is highly effective. 2）For the non-top level, improving tackle ratios to the upper body is important, but improving accuracy in tackling the upper and lower body is a challenge. 3）The tackle assist is highly effective. 4）The ratio of tackle assists occurring at the university level in Japan is higher than at the world top level. 5）For the non-top level, improving the accuracy of tackle assists is a challenge. 6）It is important to aim for tackles to the lower body while generating as much tackle assist as possible. 7）The rush defence is highly effective. 8）For the non-top level, creating the enough time to rebuild of defence line is a challenge.
