The MLB draft is difficult to predict. Players picked in the early rounds obviously have the best chance of panning out, but even for them the odds are against their success. On the other hand, sometimes a team will pull a gem out of the mid/late rounds, hitting a jackpot that no one saw coming.
The Oakland A’s have their share of sleeper success in recent years. James Naile is starting in Triple-A just a few years after being their 20th-round pick in 2015. In 2013 they nabbed Lou Trivino in the 11th round, and briefly got a big leaguer out of Jaycob Brugman in the 17th.