Parental choice among schools in England is informed by annually published school performance (league) tables. The 2006 league tables included a measure of contextual value added (CVA) for the first time. By explicitly accounting for the characteristics of a school's intake, the aim is that CVA should isolate the impact a school has on its pupils' progress and so provide a measure of school effectiveness. In this paper we use UK government administrative data to replicate CVA and other key performance measures in order to investigate the extent to which the current league tables provide the information necessary to support parental choice on the basis of school effectiveness. We find that school rankings based on CVA are largely uninformative for parents: almost half of English secondary schools are indistinguishable from the national average level of CVA.