It would not be much of an exaggeration to say that many popular and academic discussions of boxing tend toward moralism or functionalism. Of course, oftentimes, these two discussions become entangled. But the general features of each can be roughly distinguished. In the first kind of discussion we hear much about the violence that boxing demands and glorifies, the archaic morality at work in the very existence of a legalized blood sport in civilized societies, and tales of hard-scrabble youths who dream of championship belts and are exploited by unscrupulous managers and promoters. This moralist rendering of the sport is populated by a variety of normative positions--claims that seek to justify a legislative ban on boxing, arguments that try to establish the foundations for moral objections to the sport, and even attempts to defend boxing by highlighting what boxers themselves think about and learn from pugilistic practice. Paternalistic claims about the harm done to individual boxers, communitarian concerns about the corrosive effects of boxing on communal norms, and arguments in defense of the individual liberties of boxers are commonplace. In the second kind of discussion, what is central is not establishing normative grounds for the abolition, immorality, or value of boxing but rather explaining the macrolevel causes that push people into the sport. This functionalist rendering of boxing is predominated by causal appeals to background forces such as crime, social exclusion, unemployment, anomie, urban decay, street culture, and racism as various ways to explain the role and function of boxing in society. We are, for reasons sociological, historical, and economic, typically encouraged to look "beyond the ring" and examine the larger coercive social facts that force some members of a given society into the sport of boxing. In this article I draw on work in rational-choice theory to present a more philosophically robust alternative to the moralist and functionalist renderings of pugilism. Specifically, I develop relevant aspects of Jon Elster's constraint theory to outline an account of constraints in the sport of boxing. For in boxing--as in jazz or poetry--more options are not always preferable, or even rational. On the contrary, in pugilism athletes deliberately choose their constraints and reflexively incorporate a coach's or trainer's imposition of additional bounds as a crucial part of becoming skilled in their craft. My core thesis is that, in boxing, athletes undertake to bind themselves in ways that enable creativity and maximize individual skills and that sparring in a boxing gym--with its flexible constraints and approximation of what Elster calls "optimal tightness of bounds"--is a paradigmatic form of such a rational undertaking. Developing this thesis should not only help to clarify what boxers actually do but also demonstrate the rich potential of constraint theory to contribute to a better understanding of the sport of boxing. To be sure, boxers are not alone as athletes who constrain themselves and are, in turn, constrained in various ways. In fact, the analysis of boxing I develop here is part of a larger attempt to outline what I want to call a "constraint theory of sport." Most generally, such a theory holds that in competitive athletic endeavors individuals primarily strive to maximize their skills and creativity within constraints. Put simply, a constraint theory of sport is designed to explain the embedded rationality and creativity of athletic action. The argument is developed as follows. I begin with a brief summary of Elster's constraint theory (Section 1). From there I go on to suggest an account of sport as "constrained maximization" and briefly contrast that account with a related position in the philosophy of sport, that of Suits's discussion of sport as games (Section 2). In the core section of the essay, I develop a constraint theory of boxing (Section 3).… [ABSTRACT FROM AUTHOR]