I'm not a pattern expert but i agree with what mark is saying. In a PERFECT world the size of the loop would have to be predetermined. In the real world you can make small corrections in the 5/8ths part of the loop to end up at the same spot, and the Radius wont vary enough to be noticeable as compared to the initial 1/8th segment. The key to flying ANY airplane smoothly and professionally is making small enough corrections early enough that no one else can tell you are even making corrections.