Borda count
[3] The Borda count is well-known in social choice theory both for its pleasant theoretical properties and its ease of manipulation.
In the absence of strategic voting and strategic nomination, the Borda count tends to elect broadly-acceptable options or candidates (rather than consistently following the preferences of a majority);[4] when both voting and nomination patterns are completely random, the Borda count generally has an exceptionally high social utility efficiency.
[5][6] Common implementations of equal-rank or truncated ballots can also incentivize extreme burial when voters are strategic, which allows deeply unpopular dark horse candidates to win by avoiding any attention.
The integer-valued ranks for evaluating the candidates were justified by Laplace, who used a probabilistic model based on the law of large numbers.
The other commonly-used positional system is plurality voting, which only assigns one point to the top candidate.
A longer example, based on a fictitious election for Tennessee state capital, is shown below.
[14] Peyton Young showed that the Borda count gives an approximately maximum likelihood estimator of the best candidate.
The Borda count is particularly susceptible to distortion through the presence of candidates who do not themselves come into consideration, even when the voters lie along a spectrum.
Similar examples led the Marquis de Condorcet to argue that the Borda count is "bound to lead to error" because it "relies on irrelevant factors to form its judgments".
Simulations show that Borda has a high probability of choosing the Condorcet winner when one exists, in the absence of strategic voting and with ballots ranking all candidates.
My scheme is intended for only honest men.Despite its abandonment, the rounded-down Borda rule has a substantially less severe reaction to tactical voting than the traditional or tournament variants.
For an example of how potent tactical voting can be, suppose a trip is being planned by a group of 100 people on the East Coast of North America.
The Borda count is highly vulnerable to a form of strategic nomination called teaming or cloning.
Under systems such as plurality, 'splitting' a party's vote in this way can lead to the spoiler effect, which harms the chances of any of a faction's candidates being elected.
Strategic nomination is used in Nauru, according to MP Roland Kun, with factions running multiple "buffer candidates" who are not expected to win, to lower the tallies of their main competitors.
Because the harmonic series is unbounded, it is theoretically possible to elect any candidate (no matter how unpopular) by nominating enough clones.
In practice, the number of clones required to do so would likely exceed the total population of Nauru.
Before independence, and for three years afterwards, Nauru used instant-runoff voting, importing the system from Australia, but since 1971, a variant of the Borda count has been used.
[24][25] The Borda count has been used for non-governmental purposes at certain peace conferences in Northern Ireland, where it has been used to help achieve consensus between participants including members of Sinn Féin, the Ulster Unionists, and the political wing of the UDA.
The Borda count is used to determine winners for the World Champion of Public Speaking contest organized by Toastmasters International.
The modified Borda count is used to elect the President for the United States member committee of AIESEC.
The Borda count is used for wine trophy judging by the Australian Society of Viticulture and Oenology, and by the RoboCup autonomous robot soccer competition at the Center for Computing Technologies, in the University of Bremen in Germany.
The Finnish Associations Act lists three different modifications of the Borda count for holding a proportional election.
This is analogous to a Borda count in which each preference expressed by a single voter between two candidates is equivalent to a sporting fixture; it is also analogous to Copeland's method supposing that the electorate's overall preference between two candidates takes the place of a sporting fixture.
This scoring system was adopted for international chess around the middle of the nineteenth century and by the English Football League in 1888–1889.
