I love this bit:
"If the LOP is too short, you will tend to pull your shots to the right..."

In actual fact, if the LOP is too short, the recoil will smash your thumb into the point of your nose and you will bleed all over your nice new rifle!

Length of pull is correct if there's a couple of inches gap between the thumb and the nose, when the firearm is correctly mounted.

An interesting post, littlbigd, but I tend to subscribe to the notion that a rifle fits you if it fits you, so the best proceedure is to mount the rifle and then check thumb clearance, head comfort, eye alignment with the rib, etc. As suggested above, this is what a professional stock-maker would do. If he measures your forearm, head for the door!