A portion of the ROC curves for three variants of TBLASTN. The ROC curves were generated by analyzing the results of aligning 102 queries against the yeast genome. The ROC-250 score for each version of TBLASTN is included in the legend in parentheses after the name of the version. True positives are plotted against false positives, on a linear scale. The total number of true positives possible in this test set was 988. Inset: part of the same ROC curves, plotted on a different scale to show the separation between curves.