I investigated progressive coach education program (CEP) effectiveness on youth soccer coaches for their coaching practices and beliefs on heading guidelines. Data were collected using mixed methods, including two systematic observation instruments (the Instrument for Identifying Teaching Styles, and the Coach Analysis Intervention System), non-participant observations, informal and formal interviews, and document analysis. The first study described (a) how one grassroots youth soccer coach was influenced by a progressive CEP and (b) the factors that supported or negated the CEP's effectiveness. The CEP had little influence on his beliefs and pedagogies; his professional socialization was too weak to overcome his acculturation or organizational socialization. He noted enjoyment of the indirect pedagogies employed by the coach educators and interest in the content they taught. The second study described (a) how two grassroots youth soccer coaches were influenced by a progressive coach education program (CEP) and (b) the factors that supported or negated the program's effectiveness. The CEP made an impact on only one coaches' beliefs and pedagogies. His professional socialization aligned with his acculturation and organizational socialization, while the other coach's acculturation or organizational socialization was too strong to be impacted by the CEP. They both enjoyed the indirect pedagogies during the CEP, including the format and community of practice. The third study described nine youth soccer coaches' pedagogical responses to the implementation of the United States Soccer Federation's new guidelines on heading. Specifically, I determined (a) What were the coaches' perspectives and practices regarding the coaching of heading? and (b) What factors shaped the coaches' perspectives and practices? Differences in coaches' acculturation, professional socialization, and organizational socialization were responsible for the coaches' differing responses to the guidelines on heading and resulted in their assignment to one of three groups: rejectors, acceptors, and skeptics. This research highlights the reality of learning for youth soccer coaches and importance of coach educators understanding the individuals they will come in contact with during CEP, as well as the need for lengthy of CEPs and follow-up support. Encouraging signs of youth coaches' preference for learner-centered education and the educators who conducted the CEPs was shown.