A system for grading blocks may be used to improve memory usage. Blocks of memory, such as on a flash card, may be graded on a sliding scale that may identify a level of “goodness” or a level of “badness” for each block rather than a binary good or bad identification. This grading system may utilize at least three tiers of grades which may improve efficiency by better utilizing each block based on the individual grades for each block. The block leveling grading system may be used for optimizing the competing needs of minimizing yield loss while minimizing testing defect escapes.