Later-no-harm criterion

Statement of Criterion

Adding a preference to a ballot must not decrease the probability of election of any candidate ranked above the new preference.

Complying Methods

Later-no-harm is satisfied by First-Preference Plurality, Instant Runoff Voting, Minmax(pairwise opposition), Douglas Woodall's Descending Solid Coalitions method, and Random Ballot. It is failed by virtually everything else.