  When each voter rates or ranks several candidates for a single office, a
strong Condorcet winner (SCW) is one who beats all others in two-way races.
Among 21 electoral systems examined, 18 will sometimes make candidate X the
winner even if thousands of voters would need to change their votes to make X a
SCW while another candidate Y could become a SCW with only one such change.
Analysis supports the intuitive conclusion that these 18 systems are
unacceptable.
  The well-known minimax system survives this test. It fails 10 others, but
there are good reasons to ignore all 10. Minimax-T adds a new tie-breaker. It
surpasses competing systems on a combination of simplicity, transparency, voter
privacy, input flexibility, resistance to strategic voting, and rarity of ties.
It allows write-ins, machine counting except for write-ins, voters who don't
rate or rank every candidate, and tied ratings or ranks.
  Eleven computer simulation studies used 6 different definitions (one at a
time) of the best candidate, and found that minimax-T always soundly beat all
other tested systems at picking that candidate. A new maximum-likelihood
electoral system named CMO is the theoretically optimum system under reasonable
conditions, but is too complex for use in real-world elections. In computer
simulations, minimax and minimax-T nearly always pick the same winners as CMO.
