Psychostrategist was expert on predicting the behaviour of an individual in given circumstances, assuming sufficient data was available.
Carnell described himself as an "official" psychostrategist. He also mentioned exacting a fee. The accuracy of a prediction depended on the psychostrategist having all the pertinent information: in Carnell's case, he was not told until too late of Rashel being with Coser, invalidating his predictions. (TV: Weapon)