This report looks beyond high performing schools, and digs deeper into the geographical patterns of socio-economic segregation in the comprehensive system as a whole, showing the wider impacts of selection. Along with a link to an interactive map, this report provides unprecedented insight into the dynamics of secondary school admissions in England. This research brief gives an overview of the geographical analysis conducted, including local authority-level analysis of school segregation. The interactive map provides, for the first time, school-level information about how the socioeconomic profile of school intakes reflect their local area, for almost every state secondary school in England.