This article begins with an overview of some of the late Bill McWilliams's key contributions to probation research and scholarship, focusing in particular on how his work helps us think about how people experience supervision, and about how the practice of supervision should be conceived and constructed. In the sections that follow, three of the co‐authors respond to these ideas from their different perspectives as service user, as frontline probation officer, and as probation manager. In the conclusion, we summarise the discussion by focusing on the role of values, of relationships and of evidence in the reform and development of probation.