Letsos is a 3X Pan Am medalist, as well as a 3X Gracie World Champion.
Letsos began training in Jiu Jitsu in high school at the Carlson Gracie Academy in downtown Chicago, and won several matches in the Jiu Jitsu World Championships as a purple belt. In 2002 after several years training with the Carlson Gracie academy in Chicago.
The 3 week journey that Letsos intended to have ended up being prolonged and before he knew it, 4 years had passed in which Letsos trained amongst some of the best competitors of the 1990’s and 2000’s, including the famous Gracie Barra team with whom he trained and competed for. Pete The Greek’s guard passing game was well respected, this allowed him a spot at the Gracie Barra Team, at the Brazilian National Teams tournament when he was a purple belt (2002). He then lived and train Jiu Jitsu in Brazil for four years, spending many hours on the mat with Osvaldo Alves and Carlson Gracie.

Letsos has trained alongside many of the world's best Jiu Jitsu fighters and mixed martial artists, such as Fredson Paixao, André Galvão, Tony DeSouza, and Miguel Torres. He is friends with Eddie Bravo, Kenny Florian, Jeff Glover, and BJ Penn. Letsos lived and trained with Penn at his mixed martial arts academy in Hilo, Hawaii, where he eventually suffered a devastating injury to his neck while surfing.

Since then, Letsos' emphasis has been on training students in Brazilian Jiu Jitsu at his gym, Rio Jiu Jitsu Academy, in Chicago's Irving Park neighborhood and traveling and giving Seninars around the World.