The Three Key Variables of Setup

In my mind my biggest problem at the moment are what I think are the three most important variables in the setup:

• How wide the stance should be
• Where to put the ball in the stance
• How far away from the ball to stand

Being a programmer with a maths background I can see that these three variables together can be visualised by a single triangle, with the ball being one point and some part of the feet being the other two. For the short irons the triangle will be an isosceles triangle, since the ball will lie in the middle of the stance. But how far? Is there some formula that I can use to ascertain the changes in the trangles geometry as the club is changed?

My problem is that when I step up to the ball I simply don't have a clue where to put my feet. At present I make a guess at the stance width, take a practice swing and try to notice where the clubhead travels (to figure out the distance from the ball I need), and then step up hoping that it travels the same line again on the real swing. Far too much guesswork for me: I want to know how to do this right every time.

Of course, the problem could be that I'm not paying enough attention to other things, such as posture. I suppose I could have a look at that, but it introduces even more variables! Aaarrrgh!!!

I know, I know. I need some lessons. I'll probably give up eventually and have some, but It would be great to be able to figure it out for myself...