Let's assume that you and your opponent are standing face to face. When your opponent advances towards you to take hold of you by the lapel. At the same time you withdraw as much as your oponent advances. If your oponent is mentally or physically unable to let his advanced foot advance again, he will lean forward, lose his balance, and you will be able to throw him by taking advantage of gravity.

Also, it is obvious that the same thing will happen when the stability of the legs supporting the trunk is taken away. When your opponent takes a larger step forward than usual, you may sweep his advanced foot away. By doing this, you will drop him with the force of gravity acting on him directly rather than muscular strength.

It may be difficult for you, because of the weight advantage of your opponent, to lift a larger opponent with your arms. But it is easy to support him at the center of gravity with your hips as he leans forward. Look at how a heavier person can be lifted on a seesaw seesaw if you sit further away from the fulcrum. After making your opponent lean forward, support him at the center of gravity with your hips. No matter how much weight he may have, a slight pull can rotate him him over your hips. If your hips are lower than the center of gravity, then your opponent will be top heavy and his own weight will work against him causing him to fall over you. To support your opponent completely at the center of gravity with your hips is the key point of such hip throws as o-goshi.