“On ‘Mastering The 21 Immutable Principles Of Brazilian Jiu-Jitsu’, Paulo Guillobel wears a hat of a scholar and proves that, in more than 26 years of practicing, he has not only trained, taught and competed at high level, but most necessary of all, has studied the art thoroughly. Each and every student, teacher and master will no doubt make the most of the knowledge carefully organized on this book. That is by far the most productive Jiu-Jitsu book I ever read.” -Luca Atalla, Vice President and Chief Editor of Gracie Magazine Until this book, there has never been a Brazilian Jiu-Jitsu book that has comprehensively explained the most fundamental and unchangeable principles of this martial arts style. Paulo Guillobel’s Mastering the 21 Immutable Principles of Brazilian Jiu-Jitsu is a one-of-a-kind book that goes deep into the foundation of the Brazilian Jiu-Jitsu techniques and strategies. With an understanding of the 21 principles revealed on this book, any BJJ student will be capable of discover the invisible details in the back of any technique, and also consider why the techniques are being used.