A memory device comprising a main memory and a controller operably connected to the main memory is provided. The main memory can comprise a plurality of memory addresses, each corresponding to a single one of a plurality of word lines. Each memory address can be included in a tracked subset of the plurality of memory addresses. Each tracked subset can include memory addresses corresponding to more than one of the plurality of word lines. The controller is configured to track a number of read operations for each tracked subset, and to scan, in response to the number of read operations for a first tracked subset exceeding a first threshold value, a portion of data corresponding to each word line of the first tracked subset to determine an error count corresponding to each word line of the first tracked subset.