The recognition heuristic is a simple mnemonic decision strategy. In a comparison between two alternatives, one recognized and the other not, it bets that the recognized alternative is likely to score a higher value on a given criterion of interest. Yet, this heuristic is not applicable when both alternatives are recognized. We investigate a recognition-based heuristic for tasks with two recognized alternatives. What we call the source heuristic relies on episodic knowledge about the recognition sources to treat recognized alternatives as unrecognized. An experiment provides evidence to suggest that voters rely on this source heuristic when inferring the outcomes of real-world German political elections.