Leverage!
Brazilian Jiu-Jitsu is 100% the use of leverage to control an opponent. A trained smaller person can successfully submit a larger opponent via a series of positions, movements, and ultimately joint locks or chokes.
Developed by the Gracie Brothers Carlos, Oswaldo, George, Gastao Jr., and Helio, once Carlos returned from Japan after studying Judo under Mitsuyo Maeda. The brother worked their own style in to their Judo, and BJJ was born
People started to take notice of Brazilian Jiu-Jitsu after MMA started in the early 1990s. It was evident that the new style of grappling was dominating the ground.
Unlike most other martial arts, it is near impossible to train effectively in Brazilian Jiu-Jitsu without a training partner, and actual combat (Rolling). So, it important to have someone that you can trust to train with, or your BJJ career may be short lived! It can be taxing on your body, and also mentally. It can be difficult to allow yourself to be submitted, and when you break it down, the only way to get better is to be beaten again, and again, and again. Some Ego’s cannot deal with this. Many people that walk into a BJJ gym are quickly humbled. This is a good thing, it is the beginning of a new journey.
Brazilian Jiu-Jitsu is a leveler. People from all walks of live inhabit a BJJ gym. All are treated as equals (Belt rankings aside). Similarly to surfing, when you are rolling, you cannot allow your mind to stray, or something bad may happen. It is quite meditative.
Competitions are an important part of training BJJ, as although training requires physical sparring, and real situations, there is nothing quite like a competition where you are outside of your comfort zone. It truly defines where you need to focus your training.