Many softball players suffer so-called yips in pitching and throwing. However, the factors underlying this problem have remained unknown. We attempted to develop a questionnaire to assess the risk of yips based on its causes, situations, and symptoms. A mixed method study was conducted for the above purposes. In Study 1, female university softball players (N = 97) suffering yips responded to an open-ended questionnaire on the causes, situations, and symptoms of yips. These 3 aspects were analyzed qualitatively using the KJ method. We obtained 4 categories with 14 items about causes, 6 categories with 24 items about situations, and 9 categories with 36 items about symptoms. In Study 2, a questionnaire survey using 74 items developed in Study 1 was conducted with male and female softball players (N = 345). Exploratory factor analyses of the 3 aspects revealed that causes consisted of 3 factors (injury, misses, and fear) with 11 items, situations consisted of 3 factors (important situations, usual situations, and particular person/time/distances) with 18 items, and symptoms consisted of 4 factors (spasm, lack of imagery and movements, predicted anxiety, and envy for others) with 27 items. The high internal consistency, high predictive validity and acceptable construct validity of the 3 factors indicated that we succeeded in making a preliminary classification of causes, situations, and symptoms related to softball yips. A multifactorial assessment scale for assessing the risk of yips was developed based on the results of this research. Further research is need to increase the reliability and validity of this scale.