The answer is, if you learn what a school further up the food chain is doing, you can better predict what will happen at your school. By looking at reports of who s pulling from their wait lists and dates of seat deposits, you can get an idea of what to expect in your own case. To follow the food chain, start anyplace. Schools on the same line and in the same color draw from each other more or less equally, canceling out any net effect. Changes of color reflect regional subloops, simply to make the chart a bit easier to read.
Schools have no particular relationship to the surrounding schools in a different color.
I have made an enormous effort to keep schools of the same national ranking on the same horizontal line, but these rankings will vary in regional and local opinions. I'll be too busy to respond to these messages.