Over / Under passing is one of the most effective ways to pass the guard. By pinning your partner's body to the ground and controlling their hips on both sides, you have unbelievable control. Isolating their legs will allow you to minimize space but also to pass very efficiently with a very high success rate. 

In this series, Thomas Rozdzynski prepared a full system of Over / Under passing, from Open to Closed Guard. The variety of positions and passes will allow you to explore and develop this power passing full system.