However, when the absolute number of SCINS classes is considered on the x-axis, Enamine REAL Diverse expectedly plateaus first, as shown in Supplementary Figure . and it can be seen that Murcko scaffolds resulted in the lowest weighted average class spread of 0.37 (SP, eq. 1.1), but also the highest number of singletons (almost 2,000 out of the 5,699 compounds in the set, or more than a third). This is to be expected as according to the SP equation (eq. 1.1) a solution with only singletons would have an SP of 0 (which is the lowest possible value for SP).