The Officer Grade Requirements (OGR) Project provides a scientific procedure for determination of the appropriate distribution of officer grades, lieutenant through colonel, required by the Air Force. Because of its complexity the project was conducted in three phases and is reported in several papers (OGRs I, II, and III in PRL-TR-65-15, 65-18, and 66-15). This report offers detailed information concerning the derivation of a policy equation to reliably and accurately estimate the grade ratings assigned 3,575 jobs by a Hq USAF Criterion Board. The jobs in the criterion sample were evaluated in terms of merited grade and ten job requirements factors by 1,246 majors and lieutenant colonels in the field. From a list of 181 predictors the final OGR policy equation was derived through the computation of 343 multiple linear regression problems. The data from these analyses indicated that the final policy equation was parsimonious, highly reliable, and efficient in predicting the grade ratings assigned by the Criterion Board. These findings justified proceeding with further efforts necessary to determine the total distribution of Air Force grade requirements.