The onset of deregulation in the electric power sector in the recent years has brought to the fore several pronounced issues related to reliability management, necessitating a revamping of the metrics. The element of markets and economic trading introduced in the operations of power systems has seen a paradigm shift even in the way customer-say is incorporated into the reliability apportioning. In order to better appreciate the sea-changes brought forward by deregulation, identification of areas of evolving reliability research in the regulated regime goes a long way in dealing with their deregulated counterparts. This paper caters to the view to provide a pointer to the significant issues that can profoundly impact the reliability studies in the liberalized environment. Emphasis in this paper is placed on a bilateral market structure, where all participants of competitive trading have mutually agreed upon pre-defined contracts to trade energy. With a view to improvise upon the existing nascent reliability network equivalent techniques, a realistic state space selection methodology, crucial to the contingency effects' evaluation is proposed, which makes a novel use of power flow tracing procedures. This research work is intended to pave the way for robust reliability models that take into account all the structural and consequent operational transmutations in power systems, yielding a concrete possibility of implementing non-uniform reliability as per the user requirements — a situation that was not feasible in the earlier regime.