The paper offers an interpretation of pitting one’s strength and prowess against others as internal to sport competition. Historically, the majority of modern sport disciplines originated from physical activities and practices, in which two or more competitors gauge their strength and prowess in order to know who is the better. Despite the fact that pitting strength and measuring prowess remains central to modern sports, the agonistic element has been undertheorized and less studied compared to games, rules and skills, although in the last decade more researchers within the field of philosophy of sport has centered their analysis on sport competition. Taking advantage of this research, the paper proposes to examine critically the role of play and the function of rules and skills in sport competition from a triple interpretative perspective: Sport athletes gauge their own level of strength and skill by measuring their prowess against others and by being measured themselves according to their achievements.