I once ran across a trainer who firmly believed in whorlology. What I wouldn't give to talk to him again today. It was a while ago, but here is what I remember learning from him.
Position of the whorls on the head can be indicative of sensitivity level, whether the horse is right or left handed, and personality type. If the fur spins to the right, your horse is more likely to be better going to the right. Same for left sided horses. He also said that the position of the whorl like if it was closer to the right eye could be indicative of whether the horse was more touchy on the side. (I think that the side the whorl is closer to is the less sensitive side.. But can't remember.)
Positioned high on the head (above the eyes) are likely to be highly intelligent, hyper sensitive types. Not dangerous unless handled poorly. Also not horses for the average beginner until highly trained.
Whorls between the eye are likely to be sane, agreeable types. Typical steady-eddy, bomb-proof horses. Better for the beginner.
He gave me a hell of a warning about whorls below the eye, mid face between under the eye and the nostril. I remember him so clearly. He said he never handled any horses as rank or dangerous as the ones with low whorls.
According to him, multiple whorls can be indicative of multiple personalities. The horse I was riding had 2 whorls side by side and he said that could mean that the horse was more flighty and spook prone on one side and calmer on the other. I don't know if I ever did see that in the horse, I was only a lesson student.