There has been substantial progress in populating the toolkit and in developing a more sophisticated set of push and pull strategies to promote evidence-based policing (EBP) principles. The toolkit and the Effect, Mechanism, Moderators, Implementation and Economics (EMMIE) system were designed in response to common practitioner criticisms about the unnecessary complexity or long-windedness of academic research and the failure of academics to translate findings usefully for a practice audience. It analyzes the activities of the What Works Centre and some of its achievements to date. The chapter explores findings that give a sense of the extent to which the police have adopted principles of EBP. It explains findings from two case studies of potential 'opinion leaders' or 'opinion changers' working within the police. The chapter focuses on progress of the various groups involved in the What Works Centre. What Works Centres have tended to focus effort on 'push strategies' that make evidence available to decision-makers.