Modern, flatter and leaner organizations are facing a shortage of human capital in the senior executive ranks. The solution to this succession problem requires new methods for accelerating the development of the knowledge and skills required for senior executive roles. Building on the research evidence from the study of expertise we outline a construct of flexible expertise and synergistic leadership skills required to convert that expertise into effective action in senior executive roles. We then present a research program and agenda for the accelerated development of flexible expertise and synergistic leadership skills using microworld simulations, coaching and roles plays.