Na, let's don't.
First of all it's not a "system" John because I don't level tables every day. Secondly you have no idea how I went about it so telling me to "throw it out" is just as ignorant as telling me to throw my level away. To say there are "variables" is also a silly statement as again, you don't remotely know what I did there or in what order. I can tell you I spent about an hour total though. If I did do that every day and expected to be paid however I'm sure I would be considerably more competent than every "mechanic" I have personally hired to come on site. Unfortunately I find this with too many things in life. Hobby by necessity. If I could have Fedexed the entire job to Donny or gotten Glen to come here, that would have been my first choice. But that's just how it is around here. All I ask out of a professional I hire in any field is please do it better than I can with a half hour's research. It's amazing how many people claiming to be professionals in various fields are eliminated with this simple criteria. Having a machine background I have never had trouble getting three pieces of slate on the same plane and parallel to the earth's surface. If I ever decided I had to do something like this for a living I'm sure my techniques would rapidly refine for time savings, but not results. Level is level and once you get there that's it. Sorry for that fundamental truth of physics. I know some would like it to be rocket science to nourish the ego. Maybe you could bring your sting and hinge over here and double check it for me sometime?