In this paper we develop an economic model of a professional sports league, in which the teams acquire playing talent in an external market. There have been several earlier formulations of this open model and all rely upon an inappropriately specified revenue function. Team revenues should depend upon the absolute quality of the teams, as well as their relative quality measured by win-percent. An inference that has been cited widely in this literature is that revenue sharing increases competitive inequality. We show that this analysis is flawed. If the revenue function is specified appropriately, gate revenue sharing always reduces competitive inequality.