People construct knowledge through a set of highly diverse experiences. Despite being personal, this knowledge is strongly influenced by the specific context where it occurs. Such experience-based knowledge is referred to as "implicit theories" because it does not fit in with a systematic and theoretical knowledge context like that of scientific knowledge. Coaches work with a number of implicit theories about aspects such as players, competition or training which determine their professional behaviour to a considerable extent. Thirty-nine Spanish First Division coaches were asked the question "What does playing soccer well mean?" in this study. Their responses were later classified into eight different categories which show the diversity of opinions regarding this matter as well as the possible implicit theories that would guide coaches' actions.