I was wondering. In this example I use polarized photons, but maybe it is applicable to electrons and spin also. We can prepare two completely unentangled polarized photons, and send them in opposite directions to two detectors preceded by a filter at particular angles. Both of them will show a correlation between their individual prepared polarization, the angle at which each filter is oriented, and the probability the photon is detected at that side. The measurements are, of course, independent. Alternatively, we can prepare two completely entangled polarized photons, and send them in opposite directions to two detectors. This time, there will be a correlation between the relative probabilities a photon will of will not be detected, and the relative orientations of the filters. There is even a possibility to prepare the photons in some mixed state, in which some degree of both scenario´s is applicable simultaneously. So what I´m wondering about is this: To which extent is a probable outcome purely random if there is correlation in play? It seems that, at least in this particular example, entangled or not, randomness always has an amount of correlation, which in my eyes seems the opposite of randomness, to it.