This paper reports on an ongoing study of why, how, and with what consequences judges of the UK Supreme Court (the Court) disagree. It rejects the commonly accepted starting point that judicial disagreement is ‘political’ in that it can be adequately captured along a classical liberal–conservative. Instead it argues that judicial disagreement is ‘doctrinal’. We take Harlow and Rawlings’ distinction between red- and green- light approaches as a basis for constructing a doctrinal scale of judicial ideal points. Such a dimension better captures patterns of decision-making than a classical liberal–conservative scale. This paper goes beyond our published work (“Legal Ideology, Legal Doctrine and the UK’s Top Judges”, Public Law, 2016) by presenting dynamic estimates of the ideal points of the Court’s judges. Preliminary findings suggests distinct eras of consensus and dissensus, with the Supreme Court currently witnessing a period of divergence in judicial attitudes.