All-at-a-distance-forces in physics have flux like the forces magnetic, electric, electromagnetic, and gravitic. Psi has the property of acting at a distance therefore it has flux. Flux can happen when one wave intercepts another wave and a series of waves intercept each other along a line of force. If waves stop intercepting the wave of the flux to continue the series. Then flux strength decreases by decreasing; the distance the total waves of the flux, the ability of the flux to interact with the target, duration of effect, and area of effect all decrease.
In order to increase the effect of psi mastering the generating and propogation of psionic flux directly controls the probability that a psionic event will happen.