Not sure why you said that Amateur Draft players are 21 or older. People can still be drafted after graduating from high school or (in many cases) junior college. Teams generally can't draft players from four-year colleges until they complete their third year; that may be what you're referencing. (The real-life minor league Rule 5 draft allows teams to choose eligible players off lower-level teams in other organizations. A triple-A team can draft players from double-A or single-A teams, if they're eligible. Unlike the major league Rule 5, they don't have to keep them on their active roster, and the draft fee is lower.)
You're right - I'll change it. Players attending a 4 year college are not eligible for the draft until they turn 21; however, players can also be drafted out of high school.
Not sure why you said that Amateur Draft players are 21 or older. People can still be drafted after graduating from high school or (in many cases) junior college. Teams generally can't draft players from four-year colleges until they complete their third year; that may be what you're referencing. (The real-life minor league Rule 5 draft allows teams to choose eligible players off lower-level teams in other organizations. A triple-A team can draft players from double-A or single-A teams, if they're eligible. Unlike the major league Rule 5, they don't have to keep them on their active roster, and the draft fee is lower.)
You're right - I'll change it. Players attending a 4 year college are not eligible for the draft until they turn 21; however, players can also be drafted out of high school.
That comes from the MLB website: https://www.mlb.com/glossary/transactions/rule-4-draft
As you can imagine, the abundance of arbitrary rules makes it pretty difficult to nail down exactly what is and what is not allowed.