Strategic Voting, explained.
Strategic voting submits a ballot different from a voter's sincere preferences to obtain an outcome that voter prefers under a particular voting rule.
Why it happens
Your true preference is A over B over C. Three other Borda ballots are BCA, CBA and CBA. Award two, one and zero points, breaking ties C then B then A. Your ABC ballot elects C; BAC elects B. All six rankings can be tested.
Strategic voting submits a ballot different from a voter's sincere preferences to obtain an outcome that voter prefers under a particular voting rule.
Read the result
Hold your true preference fixed and change only the submitted ranking. A better outcome for that preference illustrates manipulation without changing what you value.
A worked example
An honest ballot that elects C
Submit ABC with the three fixed other ballots. B and C each receive five points, and the stated tie rule elects C.
Change your submitted ballot to BAC. B now receives six points and wins, while your true preference stays A over B over C.
Compare B with the honest winner C. The insincere ballot produces an outcome you prefer in this specified election.
OPTIONAL DEEPER DETAILGo deeper: inside the model
Inside this model
Your true preference is A over B over C. Three other Borda ballots are BCA, CBA and CBA. Award two, one and zero points, breaking ties C then B then A. Your ABC ballot elects C; BAC elects B. All six rankings can be tested.
Where this idea is useful
A practical use
A voter may need to consider how the aggregation rule converts rankings into outcomes rather than assuming every system rewards sincerity.
A common misconception
“A ranked ballot always makes honest ranking optimal.”
The incentive depends on the voting rule and the other ballots. Ranked systems are not automatically strategy-proof.
What this explanation leaves out
- This four-voter example illustrates manipulation under Borda; it does not prove the Gibbard–Satterthwaite theorem or show that every election is manipulable. Preferences and other ballots are perfectly known here.
Does this prove the general impossibility theorem?
No. It is one explicit Borda example. The theorem has a wider scope and particular assumptions about deterministic rules, preferences and possible outcomes.
What information would a voter need to know whether this strategic ballot is worthwhile?
Associated thinkers
Associations marked provisional are awaiting source review.
Further reading
Explore the original research or the teaching reference behind this experiment.