This article explores a number of themes common to the work of Gordon Smith and to more formal models of coalition behaviour, with an empirical focus on coalition bargaining in the Federal Republic of Germany. It is argued that numerical formation criteria alone are poor predictors of actual coalition outcomes, and that institutional structures and norms - particularly partisan ideology - play a decisive role. Parallels are drawn between de Swaan's 'median legislator' theory and Smith's concept of the 'politics of centrality' and two conclusions are reached. First, that the dynamics of coalition behaviour have remained remarkably stable, despite changes in the numerical composition and ideological range of the German party system. Second, that the formation of the Red-Green coalition in 1998 does represent a change in those dynamics, but that there is no evidence to suggest that the Federal Republic is moving beyond the politics of centrality.