Condorcet with Dual Dropping is a ranking system for deciding single or multi-winner contests (elections) using voted preference (or approval) ballot list or pairwise tally matrix. It computes the Cloneproof Schwartz Sequential Dropping (CSSD) and Tideman's Ranked Pair (RP) results for each contest round, and selects the combined CSSD and RP outcome with the lowest overall dropping cost. There are options to compute just the CSSD, RP, or Minimum Dropping Cost outcome, various optional pair rank and winner tie-breakers, and alternative measures of dropping cost (winning votes and/or margin). It comes as a console program and CGI executable.
