out with the claiming team. The National League (NL) was the first of the two major leagues to adopt the trade deadline rule in 1917. Originally it was enforced after June 15, but was later changed as the result of a new collective bargaining agreement. For many years, players could not be traded from one league to another without being waived by all of the teams in the trading team's league. Then an inter-league trading period was established, centered on the winter baseball meetings in December. Later, there were two "inter-league" trading periods each year, one from after the World Series until mid-December and the second from a week before spring training began until March 15. So intent were leagues on keeping their stars from being moved from one league to the other, that then–National League President Warren Giles threatened to keep NL clubs from trading major stars to the American League after the deal that sent Frank Robinson from Cincinnati to Baltimore. Assignment to a minor league team Options Options are directed by MLB Rule 11 (C). A player has a finite number of option years in which he may be moved between the major and minor leagues up to five times as of 2022; previously, a player could be optioned an unlimited amount of times subject to the 15 day wait period for pitchers and two-way players and 10 day wait period for hitters except when either the "27th man" or injured list exception applied. If a player is on the 40-man reserve list but not on the active major league roster, he is said to be on optional assignment—his organization may freely move him between the major league club and the minor league club. The rules for this are as follows. (In all cases, an assignment of a player on a major-league injured list to the minors while on a rehabilitation assignment does not count as time spent in the minors.) Once a player has been placed on a team's 40-man reserve list, a team has 3 option years on that player. A player is considered to have used one of those three option years when he spends at least 20 days in the minors in any of those 3 seasons. A team may have a fourth option year on a player with less than five full seasons of professional experience, provided that both conditions below are