An RFID reader inventories a population of tags. The reader evaluates responses from tags by categorizing them in slots. As tags are inventoried, the number of slots based on a Q-parameter is reduced. The reader addresses the tags by communicating a Q1 value for the Q parameter, generates first contents from replies received from the tags, and computes a first merit statistic based on the first contents. Next, the reader determines a Q2 value for the Q parameter, which if used in the same way would meet a preset fairway condition better than the first merit statistic. After determining the Q2 value, the reader addresses a portion of the tags by communicating the Q2 value for the Q parameter.