This chapter summarizes the book’s contribution to understanding the role of individual legislators’ attributes in the collective goal pursuits of political parties. It assesses the performance of parties on the premises derived from our theory by calculating for each party a “batting average” describing the degree to which premises of the expertise model, electoral–constituency model, and issue ownership hold for each party. It graphically depicts the parties in the book’s two-dimensional space regarding how a country’s electoral system affects a party’s dependence on the geographic location of votes and the personal votes of individual legislators. In this manner, it reveals considerable support for the theory, which states that the less parties depend on these electoral factors to maximize seats, the more they tend to use the expertise model. The more dependence in either dimension, the more the electoral–constituency model tends to explain a party’s personnel strategy. The chapter expands on the role of electoral system variation—including electoral reform in Japan and New Zealand—on party personnel practices. It discusses how our results provide new evidence for the proposition that mixed-member proportional (MMP) systems may offer “the best of both worlds” in representation, and offers a discussion of further extensions of the theory and applications of the resource-based view (RBV) of the firm to competing political parties.