This article raises important questions about whether the increasing control of early years education through performance data is genuinely a means for school improvement. This composite article, examines the pervasiveness of attainment data in early years education professional activity, its impact on early years teachers' consciousness and identity and the narrowing and instrumentalisation of early years pedagogy. The authors argue that, rather than improving quality, the current obsession with performance data and its stretch down the age range has the potential to undermine the foundations for children's personal development and learning. The article also points to the ways in which a triage effect has led to the neglect of some children in order to push targeted children over specific performativity hurdles. The discussion applies Foucault to the early education sector in England and builds upon other early childhood researchers such as Moss.