In this study an approach for testing electrode array schemes with respect to their ability to improve the resolution of methods for activation time imaging is proposed. First local linear dependency maps are computed using a virtual array method. These maps depict the torso surface areas where the body surface potential is most sensitive to changes in the transmembrane potential. The optimal number and position of the electrodes within the sensitive body surface regions was selected by constructing effort gain (EG) plots. Such a plot depicts the relative attainable rank of the leadfield matrix in relation to the increase in number of electrodes required to build the electrode array. From the sensitivity maps it was found that the BSP is most sensitive to changes in TMP on the upper left frontal and dorsal body surface. The EG analysis revealed that the optimal array meeting clinical requirements and improving the resolution of activation time imaging consists of 125 electrodes.