sentences:  Bonus babies were the group of amateur baseball players who went straight to the major leagues between the years 1947 and 1965 and received a signing bonus in excess of $4,000.The bonus rule prevented the player from spending time in the Minor League Baseball system that was, and is, the training ground for most professional baseball players in the United States, and came under criticism because it often caused such a player to languish on a major league bench instead of gaining experience in the minors.Five of the 1947–1965 bonus babies had produced Hall of Fame careers