1. A method of automated training for a router confidence engine in a call routing system, the method comprising: defining, by a computer system, a set of call routes for processing input speech utterances in a call routing system, each call route representing a specific call processing path; performing, by the computer system, initial router confidence training based on an initial set of training data; operating, by the computer system, the call routing system to assign input speech utterances to the defined call routes; collecting, by the computer system, adaptation training data based on processed input speech utterances; and re-performing, by the computer system, router confidence training based on the adaptation training data, wherein each iteration i of the re-performing occurs when 2 i speech utterances for each call route are available.