The Bonus Rule was a rule instituted by Major League Baseball in 1947 that prevented teams from assigning certain players to farm clubs. The rule stipulated that when a Major league team signed a player to a contract in excess of $4,000, the Major League team was required to keep that player on the 40-man roster for two full-seasons. Any team that failed to comply with the rule lost the rights to that player's contract. The player was then exposed to the waiver wire. If the player did remain with the team for a full two-seasons, the team could then send that player down to the farm teams without repercussions. The rule went through several variations until it was finally abolished in 1965.