In the 2006 RoboCup Virtual Rescue Robots competition, teams from different research labs developed methods for controlling teams of mobile robots in a simulated urban search and rescue scenario. The scoring procedure used in this inaugural competition rewards participants for the number of victims found, the amount of area explored in the environment, the quality of the maps created by the robot teams and penalties participants for colliding with a victim or relying on human operators. The analysis of the strategies and scores suggests that the scoring procedure may lead teams to adopt strategies that are not consistent with the needs of a real search and rescue scenario. This paper introduces Robotic Exploration Utility as a measure of exploration quality and analyzes the results of the competition based on this measure. Individual robot contributions to the system were reviewed to account for the costs associated with adding a robot to the environment, indicating that value added per robot is an important measure that is overlooked. The analysis also revealed substantial performance variation, depending on the behavior that was being rewarded, which may indicate a lack of focus for evaluative performance measures of robotic urban search and rescue systems. The Robotic Exploration Utility metric enables the research community to focus on a performance measure which reflects the needs of the domain, while allowing task performance to be easily compared across systems.