Ken Griffey, Jr. was taken with the first overall pick of the 1987 draft.

The First-Year Player Draft, also known as the Rule 4 Draft, is Major League Baseball's (MLB) primary mechanism for assigning amateur baseball players from high schools, colleges, and other amateur baseball clubs to its teams.

Unlike most professional sports, MLB does not permit the trading of draft picks, so the draft order is solely determined by the previous season's standings; the team that possesses the worst record receives the first pick. If two teams have identical records, the team with the worse record in the previous season will receive the higher pick. In addition, teams that lost free agents in the previous off-season may be awarded "compensatory" picks.

The first draft took place in 1965; it was introduced to prevent richer teams from negotiating wealthier contracts with top-level prospects and therefore, monopolizing the player market. Originally, three drafts were held each year. The first draft took place in June and involved high-school graduates and college seniors who had just finished their seasons. The second draft took place in January for high school and college players who had graduated in December. The third draft took place in August and was for players who participated in American amateur summer leagues. The August draft was eliminated after two years, and the January draft lasted until 1986.

Overall, 18 of the 45 first overall draft picks have participated in the All-Star Game, and two, Bob Horner and Darryl Strawberry, have won the Rookie of the Year Award. Twenty of the forty-five picks have been drafted from high schools, one has been drafted out of the Independent American Association, and the others were drafted from universities. To date, Arizona State University has been the only school from which multiple number-one overall draft picks have been chosen. Out of all the first overall picks, only Ken Griffey Jr. has been elected to the Hall of Fame.