I have an average of 3.5 players drafted a year in Iba over the last 20 seasons.
Here's what I have seen...
* Stats are irrelevant. Awards are also irrelevant.
* Potential and ratings matter more than anything (75%?)
* Your team's success also matters. If you make a deep NT run, the chance of your players getting drafted increases significantly, esp past sweet 16. I think this is about 10-15% of the formula. Good news: you can't lose more than 6 total (seniors, transfers, and draftees) unless you have more than 6 seniors. So if you have a stud underclassman or two but a lot of seniors, you could keep them longer than you would normally expect.
* random player personalities are the rest (10-15%). You can tell these by the responses you get during recruiting, sometimes by grades and work ethic. When you get a kind of player the administration enjoys, they don't leave as easily as the guys who are begging for handouts during recruiting and talk in ubonics.
It is not an exact science, and it really isn't IRL either. Guys leave way too early in real life and some players occasionally come back that could go top 15.
I agree with the early posts here, but PLEASE ADD TEAM SUCCESS to the equation.
After they decide to come out, its totally based on ratings as to where they are drafted.