In recent years, an increasing number of colleges and universities have been turning away from traditional letter grading systems that limit student grades to A, B, C, D, and F based on the presumption that grading systems with more flexibility are advantageous to both teachers and students. However, as with any rating system, before opting for a new grading system it is important to recognize that modifications may result in some, possibly unintended, consequences as well. In this paper, we discuss theoretical effects that including plus and/or minus grades may have on Grade Point Average (GPA) and analyze data from a School that implemented such a change. (Contains 3 tables and 1 figure.)