When i hunted in Texas 2 years back, i had this same conversation with the one guide as to what is the best way to quickly estimate a rack while in stand. His answer actually makes sense and is rather accurate. He said that on a "typical" 8 point, meaning a 4 x 4 rack, with average mass and an inside spread that is ear to ear, which he said to use 16 inches for to be safe, use a beginning score of 80 This score of 80 will be roughly what the inside spread, main beams and mass measurements will add up to on the buck. Then just look at one side of his rack, quickly estimate the lengths of his3 tines, add them together and double it and you will be in the ballpark of where the deer scores. Meaning, if you see a 8 point with a rack that is as wide as his ears, a brow tine of 4 inches, G2 of 9 inches and G3 of 7 inches, he will score roughly somewhere around 120". Obviously this isnt a foolproof method, but it will give you a starting point to quickly judge a deer while out in the woods and not having the luxury of time to analize him better.