An implantable medical device system that senses physiologic processes via multiple sensor signal configurations. The device can further process the sensor configurations to obtain additional processed signal configurations. The device can utilize the processed configurations for ongoing sensing of the physiologic process. The device can also automatically evaluate the multiple sensor configurations as well as the processed configurations and select the configuration offering the best signal discrimination to reduce oversensing or erroneously interpreting secondary characteristics of the physiologic process as corresponding to primary characteristics of the process as in double-counting. The signal discrimination can be evaluated as an absolute margin and/or a ratio between amplitudes of the primary and secondary characteristics. The signal discrimination can also be evaluated based at least in part on a calculated mean and standard deviation according to each configuration.