ABSTRACT: This chapter builds on a recurring theme in Bill McGuire's methodological works: the description of researchers' strategies in terms of their potential to facilitate or hinder progress. A common property of many long-unresolved theoretical debates in psychology is the flexibility of the competing theories: They are readily modified to accommodate unanticipated findings. Although theory modification is essential to scientific progress, repeated modifications can make contending theories effectively interchangeable, in turn making their competition illusory. Because theory competitions can be either sustained or resolved by voluntary actions of researcher/theorists, there is no way, beyond generalizing from the past, to predict that a specific theory competition will be sustained in illusory fashion. This makes it a challenge to develop strategies that will protect against the waste of research resources on unresolvable theory competitions.