David Meyer and John Will are black belts under Jean Jaques Machado and were some of the first few westerners to defeat established Gracie JJ fighters in the 80's. Both are instructors of my instructor, who is a brown belt under the JJ Machado system. I'll be attending a seminar this summer with Mr Meyer and hope to continue enhancing the techniques taught down to me by him to my instructor. Here's a roll crucifix/arm bar transition we work on often. Enjoy