This article reports on an ongoing study that investigates the development of expertise in rugby league and Australian football by Indigenous Australians as a socially and culturally situated process of learning. Focused on the sampling phase of the Development Model of Participation in Sport (6-12 years of age), it combines narrative inquiry and grounded theory methodologies to identify the important role that participation in a range of different sports and in informal games plays in the participants' development of expertise, as a process of socialisation.