International Amateur Player
Now, what makes international prospects eligible to become free agents?
The first criteria for international prospects is that the player has to be at least 16 years old prior to September 1st of that years free agency period. A pretty fair rule when we look at how these kids are already being heavily scouted since they were 13-14 years old, and 16 years old gives the prospect some more maturity to make a decision on their baseball career.
The second and last criteria a player must meet is that have to reside outside of the United States, Puerto Rico, and Canada and can not have attended any educational institution in the mentioned countries above.
So if a player comes from a country like the Dominican Republic and plays high school ball in the United States, they cannot be deemed an international free agent. Again, a pretty standard rule considering high school ball players in the United States are pretty widely scouted if they have the talent and potential to be a major league player.
If a player meets these criteria, they can be deemed an international amateur and can be selected during the international free agency period.