Great defenders cover more water. Movement over hips is so important because you’re covering so much space in defense. The quality of you as a defender is directly proportional to the amount of space you can cover. When you move over your hips—not by reaching with your arms—you keep your body line stable, your hips high, and your first step fast. That lets you do real damage on defense: you can cover more players, close gaps quicker, attack the ball, drop into the zone, and recover out of it—all without fouling.
If you don’t know the proper over-hips technique, you’ll fight the water. You end up vertical, sink, and drag your legs like rocks. That burns energy, slows your reactions, and forces desperate reaches that lead to exclusions.
You can also show this as quick bullet points in the video:
Start in drop, hips high.
Legs & hips point at shooter.
Ball goes → move over hips toward shooter.
Helper arm up while moving.
Big breaststroke kick → get vertical.
Main arm in full shot block, close the angle.
Foul only with non-blocking arm.
If no shot → use arm + backstroke kicks to reset to drop.