Cheating, it is claimed, is anathema to sport. But is this the case? In this paper it is argued that cheating is integral to modern sport, that the model of sport as 'fair play' is simply an ideological guise of amateurism. The paper focuses on the sport of professional running which, since its origins in the eighteenth century, has been a gambling sport. Strategies involving cheating to manipulate wins, or losses, have featured in this sport as ways of increasing the probability of striking successful wagers. Such strategies are an accepted part of professional running: participants anticipate and expect others to be playing it in this way. However, a distinction is made between what is referred to in the paper as 'clean' cheating and 'dirty' cheating. The former is an accepted way of the sport, the latter occurs but is deprecated. The paper explores these different forms of cheating and the athletes' responses to them. Through a focus on the discourses of success in capitalist society, a model of cheating is developed to interpret such practices. Within the context of professional running, a working class sport, it is argued that, given the habitus of its practitioners, 'success' may be measured in terms of monetary gains and the 'kick-on' in life that these might provide. Cheating practices may serve to enhance the probability of success and social mobility. Given the relatively short career spans of sports people and the costs involved in developing the requisite skills, cheating may promote success and establish a financial base for post-sport careers. The paper concludes that cheating in sport can be anticipated as a feature of an acquisitive capitalist society.