NBA: How Many Years of College Basketball Do the Best Players Need?

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Since 2006, when the National Basketball Association raised its eligibility from 18 to “one year removed from high school,” there have been murmurs that the league would want to bump it up even further. Commissioner Adam Silver said so himself, describing it as the NBA’s top priority as recently as two months ago. Cynically speaking, the only reasons to follow through with this are to bolster the bleeding ranks of the NCAA, which has criticized the NBA’s current policy of encouraging a one-and-done mentality among its students, and to alleviate draft pressure on the 30 professional basketball teams that make up the league by restricting the potential pool of players.

That is to say, an 18-year-old wunderkind can turn into a 19-year-old bullet best dodged very easily, and keeping eligibility down helps NBA general managers pick more seasoned prospects, which help them keep their jobs. No one wants to draft the next big draft bust, and while some of them — think Greg Oden — have enough talent for the No. 1 spot but don’t have the durability to match, the other half are players that just aren’t meant for the NBA.

An astute GM can hedge the bets and roll the dice on players that are red flagged and get lucky from time to time. FiveThirtyEight has brought up Jared Sullinger as one of the players with top five talent that ended up going in the back end of the first round. Nate Silver looked into the best time for an NBA team to draft currently eligible players and what that might mean for the league going forward.

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International players

It’s worth pointing out how Silver went about collecting his data. Looking at each draft from 1995 until 2013, he set out to see what sort of relationship there was between how many years a player spent between high school and the NBA, and whether that had any sort of reasonable impact upon their Win Shares, a measurement developed by baseball analysts and ported over to basketball when the typical box score started to feel inadequate. Win Shares, which split into offensive and defensive components, purport to quantify how helpful a player is on either side of the court. There’s a danger in relying too heavily on any stat that boils down the complexity of basketball into a single number, but WS is one of the best developed so far. For reference, Kevin Durant lead the league in offensive win shares this year, while Defensive Player of the Year Joakim Noah finished first in defensive win shares. It correlates well to the eye test, is the point.

Beyond, that, though, no one group suffers more from their collective risks than international players. For one thing, the group encompasses everyone from Brandon Jennings, who spent a year in Italy instead of the NCAA, to players like Nikola Mirotic, who was drafted in 2011 but has yet to make his NBA debut. As such, the international constituency suffers when it comes to first-year impact, posting a collective WS of under 1: the only group that lands in such an underwhelming bracket. Interestingly, though, international players hit their peak, just below 3 win shares, at the same time as the next group.

Juniors and seniors

Lumped together for reasons that seem to be “these players aren’t pegged to go pro before they even make it to the NCAA,” drafted juniors and seniors start off better than their foreign counterparts, peak early (between their third and fifth years), and round out the decade right about where they started, just below 2 WS. Given the fact that most players hit their basketball peaks at around 28 years old, this sounds correct — a given senior is roughly 22 upon graduation, so five years on would put him at his athletic prime, more or less.

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Sophomores

After four years in the NBA, sophomores are producing the most win shares against other players drafted at the same position, and the difference isn’t even close. “Through their first four NBA seasons, sophomores produce about 10 percent more wins than the average players chosen in their draft slots,” writes Silver, while noting that the group also makes the largest impact in year one. So why are the sophomores coming in second on this list? Mostly because their ceiling isn’t as high as their younger counterparts. Sophomores tend to peak in their fifth year, which coincidentally runs concurrent to most players’ first max contract opportunities. This can lead to situations like the Silver-cited Rudy Gay, who nabbed a max deal from Memphis and then failed to get any better, and it can also lead to the Chris Paul phenomenon, when the star player recognizes his abilities early and leaves after the team fails to gain significant postseason headway.

Freshmen (and high school)

When it comes to the ultimate and lasting impact of a draft class on the NBA, though, the answer isn’t even close. While the league hasn’t allowed prep-to-pro jumps since 2006, Silver has (correctly) lumped them together because a data set of just eight years is hardly large enough to justify drawing conclusions from. Acknowledging that this list includes players from a decade of high school straight in, 1996 to 2006, the sustained success prospects that came straight from high school or after a one-and-done college campaign are staggering. You can check out the graph, plus Silver’s thoughts on the ideas behind drafting sophomores, here. FiveThirtyEight cites the indispensable Basketball-Reference for numbers, and any chance you have to poke around that site, you absolutely should.

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