Ranked Choice Voting: Very High Resistance

Ranked choice voting is immune to the strategies with the highest likelihood of use: bullet-voting and burying. RCV is immune to bullet-voting because it satisfies a criterion known as later-no-harm, which means that ranking an additional choice on the ballot doesn't hurt the chances an earlier choice is elected. While RCV is vulnerable to compromising, the situations in which it is vulnerable are rare, measured to be "low" by James Green-Armytage's statistical analysis; plus we evaluated compromising to be only a "somewhat likely" strategy to begin with. It is technically vulnerable to the push-over strategy, but that strategy is too risky and difficult to pull off in a political election.

Two-round Runoff: High Resistance

Like Ranked Choice Voting, Two-Round Runoff is immune to the bullet-voting and burying strategies. It also vulnerable to push-over, but the implausibility of that strategy, as confirmed by the above-mentioned Dolez and Laurent study, confirm that it is a non-issue in political elections. It is, however, more vulnerable than RCV to compromising. In crowded fields, there is a motivation to insincerely vote for a candidate that is presumed to be one of the top-two vote-getters. Dolez and Laurent found this to be about 1.6% of voters in the 2007 French legislative elections — quite low, but present nonetheless.

Plurality Voting: Moderate Resistance

Plurality is trivially immune to bullet voting, burying, and push-over, since the voter cannot vote for more than one choice. It is vulnerable to compromising, which we evaluated to be only a "somewhat likely" strategy for voters to use when advantageous. That said, plurality is very frequently vulnerable to compromising, more often than any other method studied by Green-Armytage's statistical analysis.

Condorcet Methods: Moderate Resistance

Condorcet methods are vulnerable to all four voting strategies, to varying degrees. All Condorcet methods violate later-no-harm and so are vulnerable to bullet-voting. However, Condorcet methods also violate the later-no-help, meaning that a later choice can help an earlier choice, which may deter a voter who is considering a bullet vote. While Condorcet methods are technical vulnerable to compromising, it is only advantageous in the rare case that no Condorcet winner exists. There are also situations in which Condorcet methods are vulnerable to push-over, but as is the case for other methods, push-over is too risky and complicated to be plausible in a political elections. The most serious strategic problem for Condorcet methods is their frequency of burying vulnerabilities, exacerbated by the fact that burying possesses campaign incentive, near-zero knowledge, and counter-strategy.

Despite being theoretical vulnerability to many strategies, Condorcet methods make it difficult for a voter to know when and how to take advantage of the vulnerability when it exists. However, voters may bullet vote or bury instinctively, even when it isn't necessarily advantageous, because these strategies intuitively "should" work, and voter education could not truthfully teach that they never work. Of particular concern is what would happen under Condorcet when burying an opponent motivates counter-burying in retaliation. If two front-runners encourage their respective supporters to bury the other front-runner, it could lead to the election of neither: ironically it could elect the Condorcet loser at equilibrium, including in situations where even plurality voting would elect the Condorcet winner.

Approval and Range Voting: Very Low Resistance

Approval and Range Voting have very low strategic resistance. The biggest strategic concern with these methods is their vulnerability to bullet voting, a strategy that suffers from all of the motivating factors: sincere order, campaign incentive, zero knowledge, and counterstrategy. Also, unlike Condorcet methods, Approval and Range satisfy later-no-help, so bullet voting can never backfire under these methods. Approval and Range are also frequently vulnerable to both burying and compromising, rated a "high" vulnerability by the Green-Armytage statistical analysis. They are immune to push-over.

Range voting is "spreading" strategy, in which all the candidates are given either the maximum or minimum scores. That strategy can be seen as a combination of compromising and burying simultaneously.

A particular strategic concern with Approval and Range voting is the combination of bullet voting and counter-bullet-voting. Two candidates that comprise a mutual majority may face a "chicken dilemma," also known as the "Burr dilemma," wherein their supporters have to choose between approving of both, to increase the odds that at least of them wins, or bullet vote for their favorite at the risk that neither wins. If the supporters of two front-runners bullet vote and counter-bullet vote, then the outcome will degrade to the plurality result.