An important lesson for all Half Guard players. This is also very important for wrestlers making the transition to Brazilian Jiu Jitsu.
A lot of information here, including the basic Underhook to Koala Sweep, The pivot to the Navy, the next step when the step over the sweeping leg of the Koala, how to hide the ankle and to sprawl, and lastly the Knee Tap when you get to your feet.
A lot of people play a lazy Half Guard, but the reality is, at the highest level, you're losing opportunities for sweeps and to be on top by playing passively.
The moves are difficult to practice because it requires weight and resistance to understand these transitions, but it also takes a game opponent that is going to sprawl and push on the head and neck.
This is not gong to be easy, your head and neck positioning is going to be the battle, so make sure you stretch your neck before and regularly strengthen your neck at the gym.