The expression "to end up with the upper hand" means ______. [originaltext]

The hand has been a symbol through the ages and in many cultures There are hundreds of expressions-and combinations of words using hand in the English language Let us examine some of the expressions that use hand.
     To get a hand in is to begin a job, to begin to know something about it. When we learned completely, it will be easy for us. We will be able to do it hands down. If we do the job well, we may end up with the upper hand. That means to be in control or to have gained complete understanding of a situation. On the other hand, if the situation gets out of hand then, it is out of control. Then we may have to hand it to someone, to let someone else take over the business. It is time for us to wash our hands, to end it up completely. You can also lend a hand to someone but without really giving up your hand. You lend a hand when you help someone. You offer them a helping hand. If someone is kind enough to lend us a hand then we surely do not want to bite the hand that feeds us. We do not want to repay his kindness by treating him badly.