Risk factor research dominates explanatory models of youth offending and "evidence-based" policy and practice with young people in the youth justice system in England and Wales. Asset is the product of these actuarial ideas and has put the risk factor prevention paradigm into practice. This article evaluates the impact that an actuarial approach to assessment has had on both the representation of young people who offend and the way in which their behavior is explained and responded to. It describes the factors that led to the introduction of Asset, before briefly summarizing the positive assessments of Asset. It is contended that the "achievement" of actuarialism in youth justice is to render arbitrary and discriminatory practices acceptable, and apparently rational. (Published Abstract)