A metric referred to as weighted mass bias was described in but is no longer included in the ILSA scoring stage, being replaced with the more interpretable average spread. The fraction of total peak intensity from the library spectrum that have a 'matching' peak in the corresponding mixture spectrum, where matching implies a peak in the mixture spectrum within a mass tolerance window (±2𝜖) and with signal intensity above the noise threshold. The reported number is a simple arithmetic average computed based on number of available fragmentation spectra compared.