The arguments and for and against minimum grading systems have grown increasingly more intense and acrimonious in the past decade. However, there has been an absence of empirical data, theory and clear comparative analyses of conflicting points of view. Critics of minimum grading contend that the practice will produce grade inflation and social promotions of "those students receiving minimum grades" as the two chief arguments against minimum grading practices. In our retrospective study, we found no evidence of grade inflation or social promotion of those students receiving minimum grades in a large urban High School using a school-wide "macro" minimum grading system over a seven-year period. We also found most of the benefits posited by minimum grading theory, including students who received minimum grades doing significantly better on state exams than would be predicted by the overall GPA's with the opposite results being true for the other students in this High School. The far-reaching implications of these results for educators looking to implement fairer and more accurate student assessment are discussed here, including the documented benefits of minimum grading as sound educational and grading policy, and the need of a minimum-grading component in any sound grading system.