There is a construct very useful to measure the efficiency taking into account both quantity and quality, which states something like
N is the highest number that fulfils the statement "in this set, there are at least N elements having at least size/quality/goodness N".
This construct is the basis of the h-index (2005),
A scientist has index h if h of his/her Np papers have at least h citations each, and the other (Np − h) papers have no more than h citations each.
But had been previously used by Arthur Eddington to value a cyclist's performance with his Eddington number (before 1944):
the maximum number E such that the cyclist has cycled E miles on E days
This resembles also the Pareto principle (1896), when he first stated that:
approximately 80% of the land in Italy was owned by 20% of the population
Which is a sort of "inverted" version of the "h-index/Eddington number" construct (however, Pareto's principle, using that formulation, does not use the original construct).
So the question is:
Is there an earlier use of the h-index/Eddington number construct? Is this construct known with a more general name, or a more general definition?