Once in the ring the "yokozuna" takes centre stage and performs a much more complex ritual dance. The dance can take one of two forms, one of which the "yokozuna" usually chooses when he is first promoted. In addition to the slightly different routine the choice of the "yokozuna"'s ritual can also be determined by the knot used to tie the rope around his waist: the "Unryū" style has only one loop at the back, while the "Shiranui" style has two. The styles are named after 10th "yokozuna" Unryū Kyūkichi and 11th "yokozuna" Shiranui Kōemon of the Edo period, although there is no historical proof that they actually carried out the dances that have been attributed to them. Indeed there are some scholars who believe that in fact the two concerned have had their ring entering rituals mixed up by earlier historians.