Borda Count is another voting method, named for Jean-Charles de Borda, who developed the system in 1770.
Definition1.5.1Borda Count
In this method, points are assigned to candidates based on their ranking; 1 point for last choice, 2 points for second-to-last choice, and so on. The point values for all ballots are totaled, and the candidate with the largest point total is the winner.
Example1.5.2
A group of mathematicians are getting together for a conference. The members are coming from four cities: Seattle, Tacoma, Puyallup, and Olympia. The votes for where to hold the conference were:
51
25
10
14
1 st choice
Seattle
Tacoma
Puyallup
Olympia
2 nd choice
Tacoma
Puyallup
Tacoma
Tacoma
3 rd choice
Olympia
Olympia
Olympia
Puyallup
4 th choice
Puyallup
Seattle
Seattle
Seattle
In each of the 51 ballots ranking Seattle first, Puyallup will be given 1 point, Olympia 2 points, Tacoma 3 points, and Seattle 4 points. Multiplying the points per vote times the number of votes allows us to calculate points awarded:
Under the Borda Count method, Tacoma is the winner of this vote.
Try it Now1.5.4
Consider again the election from Try it Now 1. Find the winner using Borda Count. Since we have some incomplete preference ballots, for simplicity, give every unranked candidate 1 point, the points they would normally get for last place.
You might have already noticed one potential flaw of the Borda Count from the previous example. In that example, Seattle had a majority of first-choice votes, yet lost the election! This seems odd, and prompts our next fairness criterion:
Definition1.5.5Majority Criterion
If a choice has a majority of first-place votes, that choice should be the winner.
The election from Example 2 using the Borda Count violates the Majority Criterion. Notice also that this automatically means that the Condorcet Criterion will also be violated, as Seattle would have been preferred by 51 % of voters in any head-to-head comparison.
Borda count is sometimes described as a consensus-based voting system, since it can sometimes choose a more broadly acceptable option over the one with majority support. In the example above, Tacoma is probably the best compromise location. This is a different approach than plurality and instant runoff voting that focus on first-choice votes; Borda Count considers every voter’s entire ranking to determine the outcome.
Because of this consensus behavior, Borda Count, or some variation of it, is commonly used in awarding sports awards. Variations are used to determine the Most Valuable Player in baseball, to rank teams in NCAA sports, and to award the Heisman trophy.