Asana "Hatha Ratnavali" provides a list of 84 asanas, describing some of them. In the 20th century, Tirumalai Krishnamacharya taught a new system of asanas, incorporating systems of exercises as well as traditional hatha yoga, to influential Indian yoga teachers including Pattabhi Jois, founder of Ashtanga vinyasa yoga, and B.K.S. Iyengar, founder of Iyengar yoga. Together they described hundreds more asanas, revived the popularity of yoga, and brought it to the Western world. Many more asanas have been devised since Iyengar's 1966 "Light on Yoga" which described some 200 asanas; some 300 were created by Dharma Mittra. Asanas have been claimed
Ashtanga vinyasa yoga six series are: Earlier practitioners of the style report that originally there were four series on the Ashtanga syllabus: Primary, Intermediate, Advanced A, and Advanced B. A fifth series of sorts was the "Rishi series", which Guruji said could be done once a practitioner had "mastered" these four. According to Sharath Jois, one must master poses before being given permission to attempt any others that follow. However, Manju Jois disagrees. According to Manju's accounts of his father's instruction, Pattabhi Jois also occasionally allowed students to practice in a non linear format. Many of Pattahbhi Jois' students now teach their Mysore