Fig. 7.

Determining the best PSM in each strategy. Suppose, fictitiously, that a given bait is to be compared to 4 peptides (called hits). Hit 1 is discarded as its raw SPC with bait is below the imposed threshold of 7. Hits 2, 3 and 4 are candidate PSMs for bait. If $\mathrm{\Delta }m\ne 0$ for hits 2, 3 and 4, a shift may be applied, and in that case shift SPC is obtained (with shift SPC $\ge$ raw SPC by definition). In Strategy1, the best PSM for bait is hit 2, as it is based on raw SPC. In Strategy2, the best PSM for bait is hit 3, as it is based on shift SPC