The Borda count is a voting rule in social choice theory that assigns evenly spaced scores to the positions in each voter's complete
ranking of the candidates without ties. With candidates, each voter awards
points to the first-ranked candidate,
to the second, and so on down to 0 for the last (Saari 1999,
p. 10568).
If is the position of candidate
in voter
's ranking, with position 1 best, then the total score over
voters is
The candidates attaining the maximum score are the winners. Ties require a separate tie-breaking rule if a single winner is wanted. Using the
scores ,
, ..., 1 gives the same ranking of
candidates, since it adds
to every total.
Each voter contributes one point to a candidate for each other candidate ranked below it. Thus
also counts the individual pairwise preferences for
over its opponents. This is different from counting victories
in pairwise majority comparisons.
For example, suppose three voters rank above
above
, while two rank
above
above
. The total scores for
,
,
and
are 6, 7, and 2. Here
is the Condorcet winner
and is ranked first by a majority, yet
wins the Borda count.