Contest duration: sizing up the opposition?

Over 2000 years ago, Sun Tzu advised military strategists to know their own strengths and weaknesses as well as those of their enemies. Similarly, animals engaging in pairwise contests are often thought to employ mutual assessment as a means of conflict resolution, with contests being resolved more quickly the more the strengths and weaknesses of the rivals differ. In an important new paper, Taylor and Elwood argue that available evidence could be misleading and that many contests might in fact be resolved by self-assessment alone.