‘Knowing many people is good for business; keeping them apart is even better’ captures the essence of research regarding the position and shape of entrepreneurial social networks. Current research focuses on high-level relationships, ignoring underlying processes. Consequently, its applicability to novel approaches such as control-based entrepreneurship, a decision logic designed for highly uncertain environments, is limited. Fostering co-creation and strong involvement of partners, control-based entrepreneurship is conceptually at odds with current networking strategies emphasizing transactional relationships, arbitrage and brokering between contacts. In this study, we therefore re-evaluate current theories regarding network position and shape for control-based entrepreneurship. We use a computer simulation of effectuation, a prototype of control-based entrepreneurship. We reveal the starkly different mechanics that lead to a similarly positive impact of network position yet completely contrasting results for network shape. Proposing tertius iungens as an alternative theoretical foundation, we demonstrate how control-based entrepreneurship reorganizes social networks towards a dense web with few structural holes, high personal centrality and highly constrained stakeholders.