At first glance, a sloper might seem like a dumb thing because it is essentially a pattern for a super boring plain shift with nothing useful at all about it including, but not limited to, seam allowances. It vaguely resembles a pattern, except that it's missing things like design details, anything that might make you want to wear it, and any indicators of what the hell you're supposed to do with it. And this is because it is the most basic prototype for the body you are designing for, for the design elements you feel bursting out of your designer head, for all those things that will require you to develop indicators of what the hell you're supposed to do to make a garment. Problem is, in order to make use of a sloper, it helps if you have some idea of what you're doing -- but that fun will come later.
I was curious about the old-school method of drafting a sloper, and found this, which to me represents how NASA would approach garment design. I'm all for playing rocket scientist for an afternoon, but I'm not sure how the resulting garments might function if I were to rely too heavily on my math skillz. (Still, it's certainly a clearer description of the method than this, which makes me want to fling myself off the cliffs at Torrey Pines.)