In this article we position outside directors ́ contribution in the corporate value chain. Our objective is to show how outside board members may contribute to value creation through knowledge and accountability. We will also provide tools for outside board members to make contributions. The directors are accountable to balance the interest of various sets of stakeholders. It is their responsibility to use their knowledge to create values throughout the whole corporate value chain. Novel heuristic approaches to board accountability are presented. Accountability is discussed in relation to board role expectations, and we introduce a board role taxonomy. This taxonomy is related to the various parts of the corporate value chain. The value chain approach shows various requirements to the knowledge and competency of the outside directors, and to the inner working of boards. The article also presents frameworks for evaluating and analysing actual board behaviour. Board evaluations are tools that may help develop board knowledge and accountability to fulfil outside directors ́ value creative potential.