http://www.celticshub.com/2016/06/06/beating-nba-draft-importance-player-age-pick-range/Read his article to understand how he makes a formula that correlates age, draft position, and success. Making a correlation into a predictive tool is dangerous work, but it definitely adds the conversation about who to draft.
Does being younger predict success? There is no clear correlation in the top 3. However, there is a correlation between success and youth in 4-20. This makes Chriss, Bender, Murray, Ellenson, Davis, Korkmaz, etc. look a lot more interesting (even though our pick is top 3, he explains why he thinks our pick should be grouped with the 4th for this draft).
Does being older and more experienced predict success? There is no clear correlation in the top 3. However, there is clear correlation between age and FAILING to meet expectations in 4-20. This does not bode well for Hield, Jackson, Luwawu, Prince, Valentine, and Dunn (also maybe 20ish year olds like Brown, Poelti, Baldwin, Sabonis, Jones, and Skal). There is also significant correlation between being older and outplaying draft position from picks 21 to the end of the draft. Guys like Gbinje, Brogdon, Hammons, Lavert, Selden, Payton might fall into this category.