Statement of Criterion
If a majority prefers one particular candidate to another, then they should have a way of voting that will ensure that the other cannot win, without any member of that majority reversing a preference for one candidate over another.
The Condorcet and Approval methods comply with the Weak Defensive Strategy Criterion, but none of the other methods in the compliance table above comply.
WDSC is identical to the Strong Defensive Strategy Criterion (SDSC), except that the phrase "or falsely voting two candidates equal" is removed from the end. That difference allows the Approval method to comply.