During his one-on-one interview with new NBA commissioner Adam Silver at the MIT Sloan Sports Analytics Conference, Malcolm Gladwell granted Silver the ability to wave a wand and change anything about the league he wanted. (Despite the perception of predecessor David Stern, the commissioner does not enjoy such power.)
Of all the issues he has highlighted in his first month-plus on the job, Silver chose to raise the NBA's age limit, preventing players from entering the draft until two years out of high school. This issue, which was tabled during negotiations with the National Basketball Players Association on the last collective bargaining agreement, was discussed in sports lawyer Michael McCann's paper here and has been a consistent theme for Silver.
"If those players had the benefit to play for some of these great college coaches for longer periods of time," Silver said in his availability at the All-Star Game, "I think it would lead to stronger college basketball and stronger NBA ball, as well."
The implication here is that an increased age limit helps all parties. The upside for the NCAA is obvious, and NBA teams certainly would prefer more time to scout prospects. But the numbers suggest that the players themselves might not benefit as much from another year on a college court as Silver suggests.
Going back to school
Although we can't run an experiment on how things would be different with a higher age limit, there is a group of relevant prospects we can use as a point of comparison: players who chose to return to school for their sophomore seasons. Specifically, I looked at players from the past five drafts who were in Chad Ford's top 30 the summer before their sophomore year and ultimately were drafted in the first round. Not all of these players would have been first-round picks had they turned pro as freshmen, but many of them -- notably Jared Sullinger, Harrison Barnes and Cody Zeller -- passed up the chance to go in the lottery.
As a control group, I used players who actually were one-and-done from the equivalent recruiting classes, covering the 2008-12 drafts. This group is somewhat more talented -- it includes four of the five No. 1 picks -- but the sophomores are strong in their own right. Of the 14 sophomores who qualify, 12 went in the lottery, and James Harden and Paul George are now All-NBA contributors.
We're not interested in the overall performance of these groups anyway. Instead, we want to focus on how they developed year to year. That's where my NCAA-to-NBA translations come in handy. They allow us to put college and NBA performance on the same scale (using player win percentage, the per-minute component of my WARP rating that is equivalent to PER).
That shows something remarkable. On average, the sophomores who returned performed only marginally better than they did as freshmen.
Sophomore development (player win pct.)
Amazingly, of the 14 sophomores who qualify (which requires playing at least 500 minutes all three seasons, a criterion that knocks out Blake Griffin, among others), nine rated worse as sophomores than freshmen. That includes basically all the high-profile freshmen who passed on the draft and saw their stock fall.
One-and-dones develop quicker
For comparison's sake, here are how the one-and-done players who qualified developed over the same three seasons, two of them in the NBA.
Freshman development
Although this group rated slightly better as NCAA freshmen, which makes sense given their perceived higher upside, 15 of the 21 improved as NBA rookies relative to their translated NCAA performance. On average, their win percentage went up by 10.5 percent, better even than we'd expect from players of this age.
Now, this study could be picking up on the superior potential of one-and-done prospects, a possible factor in why they generally were more coveted after one year in college. However, the development advantage disappears by the time both groups are in the NBA. In their third year out of high school -- the rookie season for the sophomores and second year for the freshmen -- the sophomores actually improve slightly more. But this difference isn't nearly enough to make up the development they missed out on between their two years of college. Here's how the averages compare visually:
Why the NBA develops better
Despite the quality of coaching at the NCAA level touted by Silver, there are a variety of reasons the NBA might be a better place for elite prospects to develop. Their athletic and skill advantages, especially against the lesser foes that are commonplace on nonconference schedules, might allow them to get away with coasting rather than developing their ability. And opponents often attempt to make up that gap with junk defenses and zones that don't allow stars to showcase the strengths that will help them in the NBA.
That makes Mark Cuban's position intriguing. The Dallas Mavericks owner said last week that he thinks the NBA Development League is a better place to develop young talent than the NCAA. Although Cuban's argument was built on the ability to support players off the court, he also said there's "no question" that prospects would be better off basketball-wise in the D-League.
Because few top prospects have skipped college hoops entirely, there's no comparison group of D-Leaguers to assess Cuban's claim. But the league shares common rules with the NBA and offers a more consistent level of competition than the NCAA, two potential advantages for development.
Any changes to the age limit won't be determined until the players' association has named a new executive director. Whoever replaces Billy Hunter in that role would be wise not to assume an increase in the age limit is in the best interests of the players in the long run. Instead, recent results indicate that ensuring top prospects can come to the NBA after one season in college might be best for their development.