Interface doctrines play a key role in interlegal balancing, providing adjudicative principles by which legal orders can structure and manage the interactions between them. This chapter focuses on one particular manifestation of the metaconstitutional interface doctrine of conditional recognition, the Bosphorus doctrine of the European Court of Human Rights, under which the legal order of the European Union is presumed to offer ‘equivalent protection’ of human rights as compared to the Convention system. The chapter first briefly traces the evolution of the presumption by setting out the case law since Bosphorus. Section two proceeds to question the presumption’s normative basis, arguing that it is based on a fundamental logical slip, which is unacknowledged by the Court and has gone unnoticed in the literature until now. Section three argues that this logical slip undermines the entire Bosphorus case law, resulting in bad judging, unequal application of the Convention, and conceptual confusion: a prime example of how not to do interlegal balancing. The chapter concludes that the presumption of equivalent protection should be abandoned by the ECtHR.