A computerized method of automatically identifying nets that are statistically likely to be power or ground nets in a complex integrated circuit design. The method, which does not require a-priori information, operates by determining electrical properties of each device or device terminal that is coupled to an analyzed net, and creating a mathematical description of overall electrical properties of these various devices. The method will then compare this mathematical description with at least various preset mathematical descriptions of power nets or a ground nets. If the mathematical description fits, the invention will at least provisionally determine that said analyzed net is a power net or a ground net. The invention may also determine likely voltages for these various power nets.