Welcome to NBA Mock Draft Season. Past data can’t necessarily tell us who will be picked where, but there are a few basic facts you should know about the draft.

1.) Under the current collective bargaining rules, college players are the heart of the draft. From 2003 to 2005, the NBA drafted an average of 34 college players per year. But since the NBA instituted its ban on drafting high school players, the NBA has drafted an average of 48 college players per season.

2.) International players make up the other 1/5th of the draft selections. International players are much more likely to be drafted in the second round as teams like to stash them overseas and hold their rights until they develop. But there have been plenty of international first round picks as well. The numbers tend to ebb and flow, but in the six years since the high school ban was instituted, 28 players were selected in the first round with no U.S. college experience. Brandon Jennings wasn’t really an international player and Enes Kanter didn’t actually play for Kentucky, so if you don’t count them you have 26 international players picked in the first round. Thus, on average, there are four to five international players picked in the top 30 picks.

3.) College stat-heads have become obsessed with efficiency ratings. But while efficiency matters, assertiveness is even more critical if a player wants to get drafted. First round picks used an average of 26% of their team’s possessions when on the floor while second round picks use an average of 24% of their team’s possessions. From 2003 to 2011, only seven players used less than 20% of their team’s possessions and were selected in the first round. Intriguingly, these players all came from three schools. Three came from Connecticut: Hasheem Thabeet, Hilton Armstrong, and Josh Boone; two came from Texas, Avery Bradley and Cory Joseph; and two came from Kentucky, Patrick Patterson and Daniel Orton.

4.) Efficiency is less important than you might think. Players like John Wall and OJ Mayo didn’t actually have efficient seasons as they departed college. But NBA scouts like the fact that those players were allowed to develop their game. John Calipari didn’t hold John Wall back and only put him on the floor in can’t lose situations. He allowed Wall to make some mistakes and learn and get better. Wall’s 109.2 ORtg and Mayo’s 106.9 ORtg don’t sound like the ratings of elite players, but there was enough information on these players to push them to the top of the draft.

Since 2003, Anthony Randolph has the lowest efficiency rating for a first round selection. The former 14th overall pick in 2008 had an efficiency rating of only 97.8 in college. Perhaps this should have been a red flag about Randolph, as he hasn’t exactly become a star in the NBA. But Randolph’s situation proves that if a player has the right size and athleticism, some general managers are willing to overlook college performance.

5.) Overall, draft position is at least somewhat related to a player’s statistics. Here are the college numbers of players drafted from 2003-2011:































*Kyrie Irving was injured and played only an abbreviated season at Duke.

But the stats certainly aren’t everything.  Players with great usage rates and efficiency stats can slip, particularly if they lack size for their NBA position. A 6’7” forward that dominates in college can easily slip behind a 6’11” forward with worse college stats, because ultimately, you can’t make a player grow taller.

Athleticism also matters.

In 2005, Connecticut’s Charlie Villanueva jumped North Carolina’s Sean May, despite May’s superior statistics.

In 2008, NC State’s JJ Hickson went ahead of California’s Ryan Anderson despite Anderson’s superior statistics.

In both cases, I think the final grade had more to do with athleticism than pure size.

Regardless, for those of us that watch a lot of college basketball, the NBA draft will always remain a bit of a riddle, as good college players are often picked ahead of great college players. College performance matters when evaluating NBA draft prospects, but it is far from the only factor.