In cricket there is a moment when the batter has hit the ball, a fair catch has been taken, and the bowler appeals for the wicket. The batter faces a moment of ethical testing - should they give up their wicket by walking or stand their ground and wait for the umpire to make a decision that may be incorrect. I use this dilemma to examine the role of fair play in sport as professional practice. I begin by proposing a view of sport as about cooperation in a mutual question for excellence; while there are immediate goals such as winning games, these goals require cooperation with teammates and opponents, within a set of constitutive rules that provide opportunities to compete. The identification of a common interest and the definition of sport as a cooperative activity will allow for a broader analysis of the problem, firstly through the lens of game theory, and then through the lens of virtue ethics. Game theory allows an exploration of what happens if not enough batters walk to meet the conditions necessary for it to be in the common interest of players. That is, if it is not an ideal world, in which enough players shoulder the burden of cooperating to secure the public good of fair play - if too many batters take a 'free ride', paid for through the sacrifice of those who walk - then how do we provide assurance to the batter that their sacrifice to secure the public good will be valued? This view of cricket as a cooperative professional practice to secure a public good, allows me to develop a virtue ethics framework for this professional practice. Through fair play, cricket contributes to human flourishing. I identify the moral virtues that are habituated through cricket, so that the cricketer is able to apply phronesis and act with integrity. I use an Aristotelean virtue ethics approach to develop an account of cricket as a professional practice, with an attendant framework of moral virtues. Within this practice, our admiration for the moral virtue of the batter who walks provides assurance to the players that their sacrifice to secure the public good of fair play will be valued. I conclude by applying the virtue ethics framework for cricket as a professional practice, to other sporting contexts. Rather than the detailed application of each of the professional virtues, I will demonstrate how the virtue ethics framework applies to various issues in sports which have evolved in response to the ethical challenges presented either by the sharp practices or innovations of their participants. In this way I demonstrate how sport, as a professional practice, contributes to human flourishing through the central goal of fair play.