Isaac Doederlein is an American Brazilian Jiu-Jitsu black belt under Rubens "Cobrinha" Charles, competing for Alliance. He is a 2022 IBJJF Black Belt World Champion and two-time Brazilian National Champion, known for his guard-passing and footwork-based game. Doederlein runs Varsity Jiu Jitsu in Los Angeles and produces his own instructional courses through his official site, teaching systematic passing, guard, and submission concepts to students of all levels.