Sensorimotor theories understand perception to be a process of active, exploratory engagement with the environment, mediated by the possession and exercise of a certain body of knowledge concerning sensorimotor dependencies. This paper aims to characterise that exercise, and to show that it places constraints upon the content of sensorimotor knowledge itself. Sensorimotor mastery is exercised when it is put to use in the service of intentional action-planning and selection, and this rules out certain standard readings of sensorimotor contingency knowledge. Rather than holding between movements and sensory inputs or appearances, sensorimotor contingencies concern the suite of ways in which an object can be revealed through exploration. Sensorimotor knowledge is thus directed through experience to the world itself.