predict with navamsha [SP]

Every astrologer and the books of astrology stress the use of navamsha is added in every horoscope. Normally nit remains over looked and often remains just a decorative chart. therefore, budding navamsha. I have experienced this during my lectures in the institute pf astrology. Navamsha chart is of termendous predictive use. Senior astrologers even say that a prediction given without consulting navamsha is like committing a crime!