BJJ is THE ground fighting system, period. If you want to learn to fight or defend yourself on the ground, and you should, you need to train BJJ. The system takes a "position then submission" approach, where practitioners learn to maintain, attack, and escape from every conceivable position on the ground. BJJ has roots in judo, but has gone far beyond with respect to ground fighting.
For self defense, it's important to keep in mind that there are no strikes in BJJ. You'll need to add striking and dirty tactics to the mix. But like our recommendations for stand up grappling, it makes sense to begin training without strikes and add them in once you've got a solid grappling base. Although "going to the ground" is not ideal in a self defense situation, you never know where you'll find yourself. And, the best way to avoid ending up on the ground and being dominated there is to train clinch and Brazilian jiu jitsu + striking, so you'll be better able to avoid it.
There are countless techniques and variations on positions in BJJ. The positions and techniques listed below are those that we feel are fundamental and a necessary base for ground grappling training for self defense.
All training in BJJ revolves around sparring or wrestling. A technique is learned, drilled in isolation with progressive resistance, and then quickly thrown into the sparring mix, just as detailed in our training and clinch sections.