<p>It is generally accepted that experimental control in single-case designs require the demonstration of at least three experimental effects at three different points in time. In this brief commentary, we consider the distinct function of the manipulations of the independent variable in the reversal and multiple baseline designs that provide opportunities to show an experimental effect. Given that the multiple baseline design is characterized by multiple (and potentially redundant) opportunities to detect threats to internal validity at the outset of the design and a loss of such opportunities as the independent variable is applied across tiers, we consider what is gained by arranging more than two tiers simultaneously, at least for some research questions or contexts. We hope that this discussion of tactics in experimental design and how experimental control is demonstrated will promote further refinements to single-case methodologies to meet the needs of researchers and educators in dynamic settings.</p>