Getting under an 's center of gravity: A key skill is grappling is that of LIFTING AN OPPONENT OFF THE MAT. This is done for many reasons. In Jiu Jitsu but is mostly done from bottom to set up and lower body . Understand that you will never be able to lift bigger and than yourself until you master GETTING UNDER THEIR CENTER OF GRAVITY. only when you can under their center of gravity will you be able to lift them easily off the mat and into the move you seek to . In standing grappling this usually entails SINKING YOUR HIPS UNDER THEIRS WITH A LEVEL . In ground grappling bottom position it usually entails SCOOTING YOUR HIPS DEEP UNDER THEIR HIPS. When you do this you can lift even very big opponents. When you don't, you will be unable to lift even a lightweight. If you to make a name for yourself as a dangerous attacker from bottom position, Practice scooting under and lifting daily and soon you will be attacking with much greater effect!