  Post-election audits use the discrepancy between machine counts and a hand
tally of votes in a random sample of precincts to infer whether error affected
the electoral outcome. The maximum relative overstatement of pairwise margins
(MRO) quantifies that discrepancy. The electoral outcome a full hand tally
shows must agree with the apparent outcome if the MRO is less than 1. This
condition is sharper than previous ones when there are more than two candidates
or when voters may vote for more than one candidate. For the 2006 U.S. Senate
race in Minnesota, a test using MRO gives a $P$-value of 4.05% for the
hypothesis that a full hand tally would find a different winner, less than half
the value Stark [Ann. Appl. Statist. 2 (2008) 550--581] finds.
