Sorry, I wasn't very clear. I don't mean from the double unders. I mean when you and your partner both have an underhook and an overhook. If you don't step but he does on the switch, you will have your underhook paired with the rear leg, while he will have an underhook paired with the lead leg. This means he can lift easier with his underhook than you can, or he can whip you over easier with his overhook because you are reaching with the under.