In fencing, players not only seek to improve their own special skills, speed and strength, but also have a lot of uncertainties in execution due to many variables in the competition field, such as on-the-spot reaction and how to deal with the opponent's attack or defense. Therefore, it has become a major issue for fencers. The purpose of this paper is to explore how to improve the lunge position (the basic strike position) of fencers by using the previous uncertainty experiments to test fencers under the condition of choosing reaction time, so as to effectively improve the performance of fencers.