Duplicate detection is the task of identifying all groups of records within a data set that represent the same real-world entity, respectively. This task is difficult, because (i) representations might differ slightly, so some similarity measure must be defined to compare pairs of records and (ii) data sets might have a high volume making a pair-wise comparison of all records infeasible. To tackle the second problem, many algorithms have been suggested that partition the data set and compare all record pairs only within each partition. One well-known such approach is the Sorted Neighborhood Method (SNM), which sorts the data according to some key and then advances a window over the data comparing only records that appear within the same window. We propose with the Duplicate Count Strategy (DCS) a variation of SNM that uses a varying window size. It is based on the intuition that there might be regions of high similarity suggesting a larger window size and regions of lower similarity suggesting a smaller window size. Next to the basic variant of DCS, we also propose and thoroughly evaluate a variant called DCS++ which is provably better than the original SNM in terms of efficiency (same results with fewer comparisons).