When 1 < p <∞, maps f in W1/p,p((0,1);S1) have W1/p,p phases φ, but the W1/p,pseminorm of φ is not controlled by the one of f . Lack of control is illustrated by “the kink”: f = eıφ, where the phase φ moves quickly from 0 to 2π. A similar situation occurs for maps f : S1 → S1, with Moebius maps playing the role of kinks. We prove that this is the only loss of control mechanism: each map f : S1 ...