There are 65 real single winner elections in OpenSTV Database (stv.sourceforge.net/stvdb).While the database doesn't list the individual ballots, it does list the Smith Set for each of these races. In 63 of these 65 races, there exists a dominant Condorcet winner (the Smith set has a size of 1).
For 61 of the 65 races, the database also includes the results of applying other single-winner methods to the ballots, including IRV, Coombs, Borda, Supplementary Vote, Plurality, and Bucklin. 60 of these 61 have a Condorcet winner. Here is the Smith efficiency (frequency of electing a candidate from the Smith Set) for each of the applied methods, from best to worst: IRV, Coombs: 100% Smith Efficiency (61 of 61 races) Borda, Supplementary Vote: 96.7% Smith Efficiency (59 of 61 races) Plurality: 95.1% Smith Efficiency (58 of 61 races) Bucklin Voting: 91.8% Smith Efficiency (56 out of 61 races) - Greg ---- Election-Methods mailing list - see http://electorama.com/em for list info
