Introduction

In order to achieve peak performance in sports, physical factors, motor skills factors, psychological skills factors, and environmental factors of players must be in harmony. In addition, as players moved into elite or professional sports, there was no significant difference in physical factors or motor skills, so psychological skills of players determined performance (Jeong, 1997). Dorfman (1989) called baseball a mental game and argued that a player’s mental and psychological skills had a significant effect on game performance.

Athletes in their adolescence faced psychological difficulties due to excessive competition for rankings, excessive training, school life problems, career problems, and problems with the opposite gender (Kim, 2010). In particular, student baseball players had experienced negative emotion, low self-esteem (Shin & Kim, 2021; Shin & Yoo, 2021), stress (Shin & Kim, 2021), and difficulty choosing a career (Huh & Ko, 2019).

Meanwhile, when adolescent student-athletes worry about career, interpersonal relationships, psychological skills, and performance issues, they need advice to help them think positively (Kang & Jang, 2022). However, because student athletes were not provided with psychological skills training and appropriate counseling and do not had time to ask about personal difficulties and concerns about sports, the psychological exhaustion experienced by individuals also affected their performance (Kim, 2018). Therefore, sports psychological counseling and psychological skills training should be provided to student athletes so that they can find their own coping methods when they encounter various problems in the process of growth and development (Mamassis & Doganis, 2004; Park & Hwang, 2020; Rejeski & Brawley, 1988; Son & Ryu, 2007).

In particular, due to the nature of baseball, where psychological factors were emphasized, players must effectively cope with negative psychological states experienced in game situations through self-regulation and maintain optimal performance. One of these attempts to improve the psychological functions of athletes was psychological skills training. Psychological skills training (PST) referred to a technique or strategy that practiced and trained psychological skills that were helpful in playing the game with a positive attitude for the purpose of improving performance (Vealey, 1988). It has been reported that psychological skills training not only improved performance but also helped in personal growth (Murphy & Jowdy, 1992; Son & Yoo, 2007; Sullivan & Nashman, 1998), and even in baseball, psychological skills training helped to improve players’ emotion. It has been confirmed that it has a positive effect on emotion, self-esteem, and perceived performance (Shin & Yoo, 2021). In particular, a study by Park, Kwon, & Lee (2012) also confirmed that psychological skills training had a positive effect on baseball players’ performance strategies and team cohesion.

As stated in the introduction, the psychological factors of the player was very important in baseball, and as young players tended to focus only on physical skill training, it was time to conduct research to determine the effects of applying PST. Park and Hwang (2020) suggested that most participants in psychological skills training were biased towards adult athletes and that it needed to be applied to youth and adolescent athletes. In addition, case studies on baseball players mainly focused on improving psychological skills and performance following PST, and there was a lack of research examining the emotion, performance strategies, and perceived performance of student baseball players who experienced low performance, slumps, and stress.

Meanwhile, studies verifying the effectiveness of psychological skills training often simply compared pretest and post-test measurements without using the case study design type recommended in research methodology (Han, 2017). Lee and Yoo (2020) proposed an A-B design as a type of PST case study, considering the realistic problems that if the research period was long, distortion of the research subjects’ responses might occur in the inventory measurements and cooperation between coaches and players was difficult. In this regard, the purpose of this study was to analyze the effect of PST on mood state, sports performance strategies, and perceived performance of a student baseball player using single case study design (A-B).

Method

Results

Discussion

The purpose of this study was to investigate the effect of 8 sessions of psychological skills training on mood state, sports performance strategies, and perceived performance of a baseball player. The study participant was a baseball player who had high negative emotions and was unable to demonstrate his performance during competition due to low psychological skills. Psychological skills training consisted of MBTI/self analysis, goal setting training, relaxation training/imagery training, self-talk training, concentration training, and routine training for 50–60 minutes once a week. A discussion on the results of this study was as follows.

Firstly, PST had a significant positive effect on mood state of a student baseball player. This finding was consistent with findings from previous researches (Lee et al., 2022) that PST had positive effect of mood state (TMD). The results of this study were consistent with the study of Ko and Heo (2021), which showed that vigor increased and anxiety, depression, anger, fatigue, and confusion decreased after 16 weeks of PST intervention for golf players complaining of yips symptoms. A case study in which 12 sessions of PST was administered to a female archer with learned helplessness showed that vigor increased and anxiety, depression, anger, fatigue, and confusion decreased (Han, 2012).

These results suggest that psychological skills training is a very necessary program in that it improves positive emotions and reduces negative emotions for athletes who experience serious psychological difficulties such as slump symptoms, learned helplessness symptoms, and Yips symptoms. In follow-up research, it is judged necessary to develop and apply a program to determine whether psychological skills training is effective for athletes returning to sports during and after rehabilitation.

Secondly, PST had significant positive effects on all sub-factors of performance strategies of a student baseball player. These findings were consistent with findings from previous researches (Jang & Chung, 2017; Kim et al., 2013) that that PST had positive effect of performance strategies. In a study that applied a total of 8 sessions of PST to 20 shooting athletes (Jang et al., 2018), positive changes were confirmed in self-talk, emotion regulation, automatic performance, goal setting, imagery, relaxation, and negative thinking.

In particular, Park and Hwang (2020) confirmed that psychological skills training had a positive effect on the psychological skills of high school canoe players and suggested that psychological skills training should be applied to young students such as student athletes, youth, and adolescents. In this regard, it is deemed necessary to develop a psychological skills training program for young students such as elementary and middle school students and conduct research to verify its effectiveness. In addition, because performance strategy is a variable that affects performance, it is believed that research is needed to also investigate the relationship between performance strategy and actual performance.

Lastly, PST had a significant positive effect on perceived performance of a student baseball player. These findings were consistent with findings from previous research (Feltz & Landers, 1983; Lee & Yoo, 2020; Ma & Kim, 2011; Shin & Yoo, 2021; Weinberg & Gould, 2015; Yang et al., 2015) that that PST had positive effect of perceived performance. Actual performance is important but since sports performance varies depending on the characteristics of the opposing team, environmental factor, and the level of my team, measuring perceived performance may be a more accurate way to measure the effectiveness of psychological skills training. In this regard, follow-up research is needed to develop a scale that can measure the perceived performance of baseball players.

In this study, we explored through interviews that psychological skills training had a positive effect on emotions, performance strategies, and perceived performance. This was consistent with a previous study (Park & Hwang, 2020) that verified the qualitative effects of psychological skills training through interviews.

Conclusion and Suggestion

This study investigated the effects of psychological skills training on mood state, performance strategies, and perceived performance of a student baseball player. Through eight sessions of psychological skills training and interview, changes in total mood disturbance (TMD), performance strategies, and perceived performance were analyzed using an AB design. The results of this study were as follows.

Firstly, psychological skills training was found to have a positive effect on the mood state of a student athletes. In other words, the athlete’s TMD decreased through psychological skills training. Second, psychological skills training was found to have a positive effect on performance strategies of a student baseball player. In other words, psychological skills training was found to have a positive effect on players’ self-talk, condition control, imagery and goal setting, relaxation, and emotional control. Third, psychological skills training was found to increase perceived performance of of a student baseball player. Lastly, qualitative data obtained through interviews also confirmed that psychological skills training had a positive effect on mood state, performance strategies, and perceived performance of a student baseball player.

A summary of this study’s method, result, and limitations was as follows. Firstly, because this study confirmed the effect of PST with a single-subject/case design, it was difficult to generalize the effect of psychological skills training. In this regard, it was necessary to secure sufficient research participants and conduct research to verify the effectiveness of psychological skills training with a control group. Secondly, Weinberg and Williams (2001) stated that practical effects could be achieved only when psychological skills training was conducted over a long period of time. In this respect, research was needed to develop a program that periodically conducts psychological skills training on an annual or quarterly basis and verified its effectiveness. Thirdly, in this study, the effect of psychological skills training could not be confirmed through actual performance. In sports where it is difficult to measure actual performance, measuring perceived performance can be effective. However, it is necessary to verify the effect of psychological skills training by setting both perceived performance and actual performance as variables.