Player to be named later
In Major League Baseball, a "player to be named later" (PTBNL) is a player who, at the time a trade is made, has not been designated by the other team. It may be due to a desired player not being able to clear waivers during the season (but after the season), or a team choosing from an agreed-to list of players at a later time. This rule is not applicable in any of the other major sports.
MLB rules allow six months from the date of the original trade for it to be finalized. If the teams cannot agree on the PTBNL, then the deal is closed for cash. However, in four instances the original player traded was also the PTBNL as he was traded back to his old team.
Usually a PTBNL is a journeyman; however, some players have turned out to be productive, such as Boston Red Sox DH David Ortiz.
An interesting PTBNL situation occurred with Hall of Famer Dave Winfield late in his career: he was traded on August 31, 1994 from the Minnesota Twins to the Cleveland Indians, with the terms and conditions dependent on the number of games Winfield played for the Indians during the remainder of the season (the Twins would receive an AA-level player if Winfield played 16 or more games, or an A-level player if he played between 1-15 games). However, the MLB players were on strike and the following day the remainder of the season was cancelled (thus, Winfield never played any games for the Indians that season): the deal was settled under the cash payment rule (with Cleveland paying a token sum of $100 plus (reportedly) the Cleveland GM taking the Minnesota GM out to dinner and picking up the tab).