A search engine for selectively perform iterative compare operations between a searchable pattern and S overlapping substrings of an input string of characters includes a memory for storing a bitmap having S next success size (NSS) bits, wherein each NSS bit indicates whether an associated substring including a corresponding unique number of the input characters is to be compared with the searchable pattern in successive compare operations, and includes a compare circuit for selectively performing the successive compare operations in response to the NSS bits.