In the NBA Draft all thirty teams get assigned one draft pick for each of the two rounds. It used to be that if you were a player you could jump right from highschool to the pros, but in 2005 the NBA made a rule change.
After 2005 you had to be at least nineteen years old and you had to have graduated high school and spent at least one year in college to enter the draft. This is called the one and done rule. In my opinion this rule made no sense for players that were talented enough in high school. The negatives outway the positives from this perspective.
Another example of a player who was ready for the NBA is LeBron James. LeBron came into the NBA with sky high expectations and delivered. He is a 4 time MVP, has been in 13 all star games and has won 3 championships. He responded to the pressure by winning Rookie of the Year. He easily debunked the physicality by increasing his weight to 250 pounds to join his 6 foot 8 frame.
Colleges are hurt by the one and done rule also. Since most of the top players are only there for one year they don't care about their college.
Ben Simmons the number one pick by the Philadelphia 76ers this year achieved a GPA of less than a 2.0 and was stripped of contention for National Player Of the Year Awards. It is a big threat to the college game if we keep letting people like Simmons in because he can ruin a school's reputation.