The most important factor that differentiated Brazilian jiu-jitsu from Judo and Japanese Jiu-Jitsu was that BJJ put extreme focus on ground fighting. While Japanese Jujitsu and Judo do incorporate training in ground fighting (newaza), with some schools favoring ground techniques over throwing, no Japanese schools, with the exception of Kosen judo, put as much emphasis on ground techniques as is done in BJJ. Some, if not the majority, of BJJ schools overlook throwing techniques entirely. Such training regime is responsible for the great advances in ground fighting introduced by Brazilian jiu-jitsu. In addition, like Judo, Brazilian jiu-jitsu encourages "randori" or free sparring against a live, resisting opponent. Thus, students have an opportunity to test their skills and develop them under realistic conditions, with minimal risk of injury. Overall, while most Brazilian Jiu-Jitsu techniques can be traced back to Judo and their predecessors, the major difference is that BJJ stresses the importance of gaining a dominant position over an opponent before attempting a submission; most BJJ schools teach "position before submission". One of the things that separates Brazilian Jiu-Jitsu from other martial arts is the importance of competition. Sparring is considered essential to a student's progression. This is a "live" martial art where one can go 100% in training without fear of injuring his or her opponent. Many say that this constant training against live, fully resisting opponents sets it apart from other traditional martial arts. Brazilian Jiu-Jitsu's emphasis on joint locks and maneuvering rather than strikes means that one's technique can be practiced at full speed and almost full power, resembling the effort and technique used in a real fight. Training partners can resist and counter just as they would in an actual fight, providing valuable real-world experience should the techniques ever need to be applied in an actual fight. This practice of live training, officially called Randori but commonly known as "rolling" in BJJ circles, is considered by many BJJ practitioners to be the major factor differentiating combat sports (ex. BJJ, Judo, Boxing, Wrestling) from traditional martial arts (ex. Karate, Tae Kwon Do, Aikido, Traditional Jiu-Jitsu). Technical knowledge is judged by the number of techniques a person can perform, and the level of skill with which he performs them. This allows for smaller and older people to be recognized for their knowledge though they may not be the biggest and strongest fighters in the school. It is a distinctly individual sport, and practitioners are encouraged to adapt the techniques to make them work for their body type, strategy, and level of athleticism. The ultimate criterion is the ability to execute the technique successfully, and not stylistic compliance.