The best-known type of draft is the entry draft, which is used to allocate players who have recently become eligible to play in a league. Depending on the sport, the players may come from college, high school or junior teams or teams in other countries.
An entry draft prevents expensive bidding wars for young talent and ensures that no one team can sign contracts with all of the best young players and make the league uncompetitive. To encourage parity, teams that do poorly in the previous season usually get to choose first in the postseason draft.
Other types of drafts include the expansion draft, in which a new team selects players from other teams in the league; and the dispersal draft, in which a league's surviving teams select players from the roster of a newly defunct franchise.
Drafts are permissible under anti-trust law because they are included in collective bargaining agreements between leagues and labor unions representing players. These agreements generally stipulate that after a certain number of seasons, a player whose contract has expired becomes a free agent and can sign with any team. They also require minimum salaries for newly drafted rookies.
The entry draft was invented by National Football League Commissioner Bert Bell in 1935 as a way to restrain teams' payrolls and reduce the dominance of the league's perennial contenders. It was adopted by precursor of the National Basketball Association in 1947; by the National Hockey League in 1963; and by Major League Baseball in 1965.
Drafts are virtually unknown to international soccer and other professional sports outside North America, where most professional clubs obtain young players through purchase or developing youth players through their own academies.
Draft order in the NFL is determined in a reverse-record order (the previous season's worst team picking first, the Super Bowl winner picking last). There are seven rounds of the draft, so each team can have seven selections each. But trading draft choices between teams is common practice, and some teams may receive extra picks under some circumstances, so many teams may have more or less than seven selections.
The NFL Draft has become one of the key events on the American football calendar. It is held in April at New York's Radio City Music Hall and aired live on television.
The NBA draft, held in a New York theater each summer, is only two rounds long. Instead of automatically granting the top pick to the worst team from the year before, the NBA holds a draft lottery to determine who chooses first. The top three picks are allocated by chance among the 14 teams that did not make the playoffs the year before. This discourages a team from losing on purpose to get a better draft pick.
NBA teams choose players from the NCAA and from teams overseas. It was formerly common for players to be chosen directly from high school, but in 2006, the NBA required that players wait a year after high school before playing in the NBA. Almost all top U.S. players thus play at least one year in college.
The NHL operates a seven-round off-season draft. Like the NBA, the NHL uses a lottery system to determine which team gets the top pick, with the worst five teams eligible. Any North American player age 18-20, and any overseas player over 18, is eligible to be selected. Players are generally chosen from junior hockey teams, high schools, the NCAA and overseas clubs. The NHL rotates the draft's location among cities with teams in the league.
The junior leagues that make up the Canadian Hockey League also hold drafts of teenage players in their territories.
Major League Baseball holds two drafts each year. In June, the First-Year Player Draft, MLB's entry draft, takes place. Only players from Canada, the U.S. or a U.S. territory may be drafted; players from elsewhere are free agents and can be signed by any team. Draftees are high-school graduates who have opted not to go to college; or college baseball players who have played three years or turned 21. The draft lasts up to 50 rounds. The MLB entry draft generally receives less attention than the drafts in other American sports, since drafted players usually spend several years in the minor leagues before they crack the Major League team's roster.
In December, MLB holds the much shorter Rule 5 draft. If an organization keeps a player in the minor leagues for a certain number of years, other teams can draft him in the Rule 5 draft. The drafting team must keep the player on its major-league roster; it cannot put the player in its own minor-league system.
Every spring, the WNBA Draft is held in the city that hosted the NCAA Women's Championship. The draft is three rounds long with each of the 14 teams in the league (trades aside) getting three picks. Draft order for teams that made the playoffs the previous year are based on team records. The team with the highest previous record will pick last. Since eight teams qualify for playoffs, the bottom eight picks are determined by this method. For the remaining top six picks, a Draft Lottery is held for the six teams that did not qualify for the playoffs.
In Australian rules football's premier competition, a draft was introduced in 1986 (when the competition was then known as the VFL). This was in response to the increasing transfer fees and player salaries at the time, which in combination with declining attendances, threatened to derail the league. In the AFL Draft, clubs receive picks based on the position in which they finish on the ladder during the season. The draft is held in November, with a pre-season draft in December.