Mental technique is a crucial aspect of Jiu Jitsu that prolongs past the floor covering
https://www.scribd.com/document/846419661/Your-Overview-to-Gracie-Barra-Jiu-Jitsu-in-Phoenix-Metro-Courses-and-Neighborhood-137980
Mental self-control is a vital element of Jiu Jitsu that expands beyond the floor covering