What is the origin of the idiom "upper hand" and when to use it?

The origin of the idiom "upper hand" can be traced back to the game of cards, specifically to the game of whist, which was popular in the 17th and 18th centuries. In whist, the term "hand" referred to the set of cards held by a player. The player who held the superior or stronger combination of cards, particularly those with higher ranks, was said to have the "upper hand." This player had a better chance of winning tricks and gaining an advantage over their opponents. It is commonly used in competitive scenarios, such as sports, business negotiations, conflicts, or personal relationships, where the concept of advantage or dominance is relevant.