Mapping accuracy of RMAPQ criterion under varying parameters. Reads with length from 25–36 nt were mapped and 0,1, or 2 mismatches were allowed at high quality bases defined by quality score cutoffs of 4 (d) or 8 (a-d). For reference, mapping performance of RMAPM criterion with at most 2 mismatches is also shown. (a) The BAC coverage; (b) the mapping selectivity; (c) the overall mapping accuracy (equal to the mean of the BAC coverage and selectivity).(d) 2-D performance comparison in both BAC coverage and selectivity of RMAPM and RMAPQ.