Abstract: 1. In a guided missile fuze system that has optimum kill probability against all sizes of targets, the combination comprising:(a) a fuzing channel for generating an output pulse in response to a received target signal after a predetermined time delay from the time said target signal is received,(b) a guard channel for generating an output pulse in response to the loss of a target signal detected by said guard channel,(c) and a firing circuit coupled to the outputs of said fuzing channel and said guard channel for firing the fuze in response to a firing pulse received from either of said channels.