75 Point Explanation
This requires that either the load pick points be perfectly symmetrical in relation to the load CG, or that one or two legs of the sling be adjustable in length and some sort of tension meter be used to determine how much weight each leg is bearing. It is safer to assume that only two legs of a multi-leg sling are taking most of the weight, and then select rigging equipment accordingly. (While they may not support much weight, the other legs of a multi-leg sling will help balance the load for better load control).