Urban science is the planning branch that uses large scale data to establish new ways to govern cities, being systems of urban assessment an example of its contemporary manifestation. What Works Cities (WWC) from Bloomberg Philanthropies and Leadership in Energy and Environmental Design for Cities and Communities (LEED© CC) from US Green Building Council are examples of such systems, the first dealing with data management and the latter with environmental sustainability. This paper aims to assess how these systems affect urban policy by means of their evaluation methods. Both systems are presented and their certifications geolocated. It is argued that these systems focus on process, and not results, leading to an ambivalent set of certifications. At last, it is suggested that the same transparency promoted by these systems in their candidates’ assessment should be applied to themselves, in order to guarantee the adequacy of their certifications.