Another example of this sort of thing (that is vaguely related in that it's commonly used as a metric) is (what I call) the Matthew's Correlation Coefficient ht

Another example of this sort of thing (that is vaguely related in that it's commonly used as a metric) is (what I call) the Matthew's Correlation Coefficient https://en.wikipedia.org/wiki/Phi_coefficient https://en.wikipedia.org/wiki/Phi_coefficient > In machine learning, it is known as the Matthews correlation coefficient (MCC) ... introduced by biochemist Brian W. Matthews in 1975.[1] Introduced by Karl Pearson,[2] and also known as the Yule phi coefficient from its introduction by Udny Yule in 1912