Primary school reception baseline assessment was designed to produce a single "baseline" data figure on the basis of which young children's progress across primary school could be measured and accounted for. This paper suggests that within the context of punitive performativity, head teachers might be considered "irresponsible" if not engaging with the new accountability measure in its voluntary year. Using DfE-accredited baseline assessment providers blurred the distinctions between not-for-profit social enterprises, digital policy innovation labs, edu-business, and the state. It is argued that through a process of networked governance, these cross-sectoral organisations successfully enticed some primary schools with the "moral economy" of using baseline assessment. It is argued that baseline's simplistic reductionism allowed for the economisation of early years education assessment and for its commercialisation of comparison. This paper reports on a sample of five head teachers, taken from a much larger study that used a mixed-methods approach involving a nationwide survey (n = 1131) and in-depth interviews with reception staff and head teachers in five geographically disparate primary schools. Baseline assessment was "withdrawn" by the DfE in April 2016, quite possibly because of campaigns by early years organisations, the government's own report showing that the three separate baseline datasets were incompatible, and national research funded by the teachers' unions, a small part of which is reported upon here.