In this paper we present a new method, the so-called - tunnel, that can be used to quantify the simulation-reality-gap by comparing the behavior (the state-trajectory) of a baseline system (for instance a real robotic system) and a model of this system (e.g. a physicbased simulation). With this -tunnel, the impact of a change of the model's parameter can be analyzed. Furthermore, we present an approach to automate the optimization of these parameters and present some results obtained on a robot system that is based on a BRIOR labyrinth game.