Philosophic inquiry into the mental states of elite athletes during skilled motor performance continues to grow. In contrast to the bulk of these works that focus almost exclusively on skillful performance, this paper examines athletic motor behavior from a point of inexactness – or even failure – in athletic performance. Utilizing the works of Michael Polanyi, who believed that both ideas of achievement and failure were equally necessary to understand the behavior of living things and their physical actions, I examine (...) the notion of failure as a framework to scrutinize the cognitive processes occurring during the development and performance of skilled motor behavior. After reviewing Polanyi’s conceptions of personal knowing to locate the source of inaccuracy in human activity, I present Polanyi’s distinction between two kinds of mistakes and apply each to inaccurate sport performance. I then suggest that mistakes in sport should be re-conceptualized beyond their current negative connotations. Instead, conceptions of mistakes should also include respect for ‘man’s most distinguished act’ – that being the production of knowledge. From this expanded perspective, the value of inexact motor performance can be found in addition to notions of uncertainty and skill development in what Polanyi calls ‘metaphysical implication of a groping for reality’. In some final thoughts, I will suggest future implications of the value of the inexact on broader sport issues. (shrink)