 The alternatives are multi-member districts or the election of a body by the whole electorate voting as one constituency.A number of electoral systems use single-member districts, including plurality voting (first past the post), two-round systems, instant-runoff voting (IRV), approval voting, range voting, Borda count, and Condorcet methods (such as the Minimax Condorcet, Schulze method, and Ranked Pairs).Of these, plurality and runoff voting are the most common.