As a player, your hips can make the difference between a goal or a near miss, a beautiful pass or a stump, a lovely through ball toward goal or a pass cut off by a defender, etc. When your hips are closed, you have no idea how the opposition is marking you(excluding scanning), where your teammates are, what is the nearest pressure, etc. However, a tiny detail of keeping your hips open can make a huge difference. Keeping your hips open can help you see the whole field around you as you take in vital information. If you receive the ball, all you need is one touch to drive forward and if a defender is marking you, all you need to do is scan over your shoulder, see how he is positioned, and body feint the defender before you have space to pass, shoot, dribble, etc. So in summary, the small change of opening up your hips can make a huge difference on the game.