Unlike draft picks in the other major professional sports, there is no instant return for MLB clubs, which have to patiently wait for their amateur selections to work their way through the minor league ranks before receiving an opportunity to show what they can do against big league competition.
That said, all draft picks aren't created equal—and some move through their respective team's farm systems faster than others. While college-age players are typically the prospects that move the quickest, due to their maturity, both mentally and physically, its not unheard of for a player drafted out of high school to follow suit.