This time a year ago, Oklahoma State guard Marcus Smart was one of the hottest prospects of the 2013 NBA draft, and he looked every bit the part of a marquee one-and-done player.

He was a top-five lock and potential top-three pick in a subpar draft class. Yet in April, he withdrew his name, opting to stay in Stillwater for another year. We were surprised that he didn't make the jump, but at the same time, we weren't too worried about his outlook heading into the 2014 draft.

Fast forward to the spring of 2014, and we have to ask: Did he help or hurt his draft stock by returning to school for his sophomore year?

It's tough to look at the sequence of events and rationalize that he helped his draft value. Even though his decision was highly respectable, he ended up doing more harm than good when it comes to his short- and long-term NBA status.

When you consider his marginal improvement as a sophomore, the intense scrutiny of the draft process and how loaded the 2014 class is, his cachet took a noticeable hit over the past 12 months. His Cowboys were bounced in the NCAA round of 64, and he'll probably land in the No. 6 or 8 range on draft night instead of in the top five.

Smart's decision was well-intentioned. I won't knock the fact that he stayed to enjoy more of the college experience and that he got another year of education. But from a business and basketball standpoint, it's usually not the best choice.

There's a widespread myth that freshman NBA prospects are prudent to spend another year in college. It's especially misleading in the cases of mature players like Smart who played big minutes during their freshman campaigns.

For most top prospects, the quick departure is simply more beneficial for them financially and more advantageous for their basketball growth.

Kevin Pelton of ESPN.com (subscription required) recently did a study comparing one-and-done prospects and their two-and-through counterparts from the past five seasons. The results showed that the one-and-done youngsters actually developed faster and posted better WARPs (Wins Above Replacement Player) in their first couple years in the league.

Billy Haisley of Deadspin.com noted that Pelton's findings jive with common sense:

Of course players improve more in a professional environment where their full focus is on basketball, rather than in a semi-professional one where they have to put a certain amount of time into struggling through their online basket-weaving courses. More than that, athletes' long-term development isn't a big concern for most college teams. They're out to win, and they make do with what's available to them.

Haisley went on to state the fundamental principle that prospects become less valuable over time, saying that "Players stand to lose millions by shortening their already brief peak earning years, and consequently others stand to gain millions from them doing so."

Pelton and Haisley's assertion that, "in fact, the college sophomores barely improve at all, and often regress," is certainly applicable to Smart.

OK State's star playmaker returned to college hoping to improve as a point man and outside shooter, but he hardly moved the needle in those areas. It became apparent that he's still not a great mid-range creator off the bounce, and his three-point shooting improved only by a hair. 

Let's take a look at some key sophomore stats compared to his freshman campaign.

As you can see, his progress in critical areas was minimal, and he was actually less efficient on jumpers inside the arc. 

This marginal improvement was nowhere near enough to boost or even maintain his top-five stock in this year's draft. A slew of 18- and 19-year-olds with tremendous physical tools pushed Smart down draft boards. The allure and upside value of Andrew Wiggins, Jabari Parker, Joel Embiid, Dante Exum and Julius Randle all trumped Smart's extra year of seasoning. Even less productive youngsters such as Noah Vonleh and Aaron Gordon have stolen the spotlight from Smart.

Last year, we were impressed by Smart's leadership and versatility, as he looked like a magnificent combo-guard option who would be able to handle the rigors of the NBA backcourt. These days, the narrative among scouts and executives is much different.

More time in college meant more opportunities to spot holes in his game, and his previously admirable freshman leadership turned into a sophomore's inability to get his team over the hump.

A few weeks ago, B/R College hoops Lead Writer Jason King talked about Smart's declining stock, and how it had to do more with his shooting than his infamous fan-shoving incident.

Yannis Koutroupis of Basketball Insiders noted that, while Smart's draft didn't necessarily take a dive, he definitely didn't help his NBA cause.

As the old saying goes, "hindsight is 20/20." It's easy for us to criticize Smart's decision now that it's in the rear-view mirror, and at the time, he believed he was doing the best thing for his collegiate and professional career.

He would never publicly denounce the decision at this point, because that doesn't do him any good from a PR standpoint. But privately, I'm sure he would admit that if he could go back and do things differently, he would.

At this juncture of the one-and-done era, especially after a situation like Smart's, talented first-round-caliber freshmen should consider the benefits of turning pro early. The NBA or NBA D-League competition is a much more productive environment for growth and preparation for a pro career.

Haisley explained that Smart's slide down draft boards is a clear warning to future ballers: "He's more a cautionary tale, a case study in why no one should attach moral value to what is, in the end, a simple economic decision."

Smart's competitive nature and versatility will enable him to survive and have a solid career, so it's not the end of the world for him.

But it's impossible to deny the bottom line: By returning, he lost money, squandered crucial time for development and put a dent in his own draft stock.

Dan O'Brien covers the NBA Draft for Bleacher Report.

Follow him on Twitter: @DanielO_BR