Principles
To understand Brazilian Jiu-jitsu, you must understand the difference
between a grappling art and a striking art. Grappling arts (such as Jiu-jitsu
and Judo) use wrestling-like holds to control an opponent, while striking arts
(such as karate) use kicks and punches to incapacitate an opponent. Striking
arts work best when you know an opponent is there and can launch an attack
before he is close. Grappling arts are designed for close contact, so even if
you have been attacked from behind or caught in a clinch you will have a
range of responses at your disposal.
Gracie Jiu-jitsu famously turned the martial arts world upside-down by
showing that, when flat on his back with his opponent on top of him, a skilled
Jiu-jitsu practitioner was still in an extremely favorable position. Having an
instant and effective reaction to an attack makes all the difference in the
outcome, and the Gracie self defense system places much emphasis on the
element of surprise.