If you want to really see a drop, especially with Chad Ford, look at the foreign players who don't come out when their stock is high. Porzingis is an exception as most end up like Pavel Podkolzine ("My head says Bosh could be a real star in a year or two. But my heart says Podkolzine here.") or Maciej Lampe. Euros routinely get exposed if they don't strike when the iron is hot.

I did a quick version of what you're talking about back in the day and I found that high schoolers taken in the first round had less of a bust percentage than college kids. My guess is that it is the same with one and doners. There are always kids who wouldn't make it but the "They would have been better if they had stayed" is 100% opinion. It is in no way, shape, or form a given that kid would get better if he stayed in school and he also risks injury to play for free. And it's not like it necessarily helps them mature either. (And, not to pile on, in many cases, college doesn't prepare kids for their NBA position.)

The only thing that does help IMO is that sometimes the kids in general could benefit from having lower expectations. Andre Drummond's career is likely better off after he struggled a bit at UConn and fell from being a top 2 pick. I think Skal will benefit from it this year.

But the decision ultimately depends on the kid. Some guys could use another year to become the man or boost their confidence, some guys need to start learning the pro game and take a step up in talent level of competition. To me, grown men bashing a kid for making a decision he and his family thinks is best for them is one of the most frustrating things to watch.

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NBA MOCK DRAFT #1 - https://thecourierclass.com/whole-shebang/2017/5/18/2017-nba-mock-draft-1-just-lotto-and-lotta-trades