If new CP violating physics contributes to neutral meson mixing, but its contribution to CP violation in decay amplitudes is negligible, then there is a model independent relation between four (generally independent) observables related to the mixing: the mass splitting (x), the width splitting (y), the CP violation in mixing (1-|q/p|), and the CP violation in the interference of decays with and without mixing (). For the four neutral meson systems, this relation can be written in a simple approximate form: ytan x(1-|q/p|). In the K system, all four observables have been measured and obey the relation to excellent accuracy. For the Bs and D systems, new predictions are provided. The success or failure of these relations will probe the physics that is responsible for the CP violation.