Do underclassmen actually improve their draft status with an extra year in school?

The UCLA Bruins Basketball team is losing two sophomores and one freshman to this year's NBA Draft. Kyle Anderson was a done deal before the season started, and we were expecting Zach LaVine to leave school after a breakout OOC schedule. Jordan Adams was unexpected--and a killer. Many of us believed he would certainly improve his pro prospects by returning for his Junior year, including yours truly here, here and here.

Is the logic behind our Monday morning NBA GM'ing right? In an article focusing mainly on Juniors, Gary Parrish disagrees. His two main arguments:

The problem with this unsolicited advice is that it ignores two realities.

1.Juniors who are borderline first-round picks or projected second-round picks don't usually solidify a place in the first round with a senior year of college.
2.Contrary to popular belief, the overwhelming majority of second-round picks aren't screwed. In fact, they usually end up with an NBA contract of some sort.

According to Parrish, Seniors have not had a big presence in the first round:

An average of just five seniors per year have been selected in the first round of the past five drafts, and, on average, only one senior has been picked in the lottery. So the idea that a junior who is a projected second-round pick can expect to return for his senior season and become a lottery pick is an idea rooted in fiction because that almost never happens. In fact, 17 of the 26 (65 percent) seniors who have been selected in the first round in the past five drafts have been picked between 20 and 30, and, again, only five seniors, on average, have been selected in the first round of the past five drafts.

I don't think that stat proves anything because the biggest stars are all freshman and sophomores in the one-and-done era, but the underlying point, that a a college player is a known quantity by the time he is a junior and is unlikely to improve his draft status significantly by staying for another year, is well taken.

Parrish supports his second point with these stats:

Being picked in the second round isn't the death sentence many pretend it to be because the overwhelming majority of college players selected in the second round do actually end up in the NBA, one way or another. In the past five years, 117 college players have been picked in the second round, and 93 of those have signed some sort of NBA contract. That's 80 percent. And even if you don't end up in the NBA as a second-round pick, there's usually a legitimate European option available, meaning prospects like Stokes and Johnson, even if they're not picked in the first round next month, will either still land on an NBA roster or in Europe with a contract in excess of $100,000 annually.

Again, I agree with the sentiment, but the type of contract and the salary indicated are vague. I've mentioned this Forbes article before. Even the 30th pick of the first round gets a three year guaranteed contract worth $927,000 per year. So is it worth doing whatever it takes to move from pick number 31 to 30?

You can actually find a lot of statistics that suggest the second round isn't so great. The washout rate is very high.

In the end, it is true that you can't change the spots on a leopard. If you are borderline or a second rounder, then perhaps that's where you'll stay. Self-knowledge is priceless.

In the case of Jordan Adams, he was probably told he'd be a late first rounder, but ignoring that for the moment, the arguments fall on both sides. The issues with his athleticism are known, and they won't go away. However, there were extenuating circumstances in the 2013-14 season. Jordan was coming of a serious foot injury that kept him off the practice court from approximately March to October.

We'll never know what could have been next season with Jordan Adams on the team, but let's hope he made the right decision for himself.