In bridge

Contract bridge

Contract bridge, usually known simply as bridge, is a trick-taking card game using a standard deck of 52 playing cards played by four players in two competing partnerships with partners sitting opposite each other around a small table...

 and similar trick-taking game

Trick-taking game

A trick-taking game is a card game or tile-based game in which play centers on a series of finite rounds or units of play, called tricks. The object of such games then may be closely tied to the number of tricks taken, as in plain-trick games such as Whist, Contract Bridge, Napoleon, Rowboat, and...

s, the term pin refers to the lead of a higher card from one hand to capture a singleton of lower rank in an opponent's hand.

Example

South wants five tricks from this suit. If the opponents' cards split 3-2 and they defend rationally, South must lose at least one trick – dropping a singleton king won't help South. However, if East holds the singleton jack then South can begin by lead the queen and pinning the jack. Provided declarer can re-enter his hand at least once, he can then take up to two finesses

Finesse

In contract bridge and similar games, a finesse is a technique which allows one to promote tricks based on a favorable position of one or more cards in the hands of the opponents....

to capture the king.

The tactic is also available to the defense, but it is more difficult to find when declarer holds the singleton.