The decision on whether to refresh or retire a memory block is based on the set of dynamic read values being used. In a memory system using a table of dynamic read values, the table is configured to include how to handle read error (retire, refresh) in addition to the read parameters for the different dynamic read cases. In a refinement, the read case number can used to prioritize blocks selected for refresh or retire. In cases where the read scrub is to be made more precise, multiple dynamic read cases can be applied. Further, which cases are applied can be intelligently selected.