There is an increasing interest for the role of social positions to understand evolutions andchanges within organizational elds. This paper advances a new approach to understand howactors manage their connections within an organizational eld and how this in uences theirability to shape the eld and its speci c institutions. Precisely, we want to explain how institu-tions (formal and informal) of the eld come to support more the interests of some players thanothers. To do so we focus on the positions of actors in the eld and their strategies of relationalbrokerage. We de ne two di erent types of brokerage: a structural one, in the social networkanalysis tradition; and an attributive one, which relies on the relational structure of actors butalso takes into account their social characteristics.