AP Hoops: The Secret Stuff Behind Call-Ups

Want to know who's the next player to get an NBA Call-Up? There's one stat that stands above all others.
Welcome back to school.

As you may (or, depending on how your summer went, may not) remember, I was your tour guide through the whimsical world of advanced metrics last season, introducing you to statistical concepts and applying them to the NBA D-League. Need a refresher on the basics? Take a minute and look through the archive.

All set? Good. Now that we’ve gotten out the cobwebs, it’s time to dive back in for Year Two.

Hundreds of players – literally hundreds – pass through the NBA D-League each year. Top performances range from big nights, such as Kenny Hayes’ 53-point outburst, to big stretches, such as Stefhon Hannah’s impressive streak in late March. Which got me thinking…how are GATORADE Call-Ups really determined? What really matters? Are there certain things that NBA teams look for? And, more interestingly, are there certain stats that can be used as Call-Up predictors?

To answer these questions, I sorted through a number of NBA D-League statistics from last season and cross-referenced them with the list of 43 players that got called up to the NBA. Although there isn’t one particular stat that is a picture-perfect Call-Up indicator, I did observe some interesting trends:

The percentage of a team’s FGM that a player assists

Ranks Player AST%
AST% is a statistic measuring a player’s ability to facilitate an offense. Given that many NBA D-League Call-Ups assume backup PG duties, this statistic’s importance makes perfect sense. As a result, six players whose AST% exceeded 25% received Call-Ups last season: Terrell Harris (26.6%), Courtney Fortson (27.2%), Carldell Johnson (27.7%), Donald Sloan (30.3%), Jamaal Tinsley (32.4%), Walker Russell (39.7%).

Shooting efficiency accounting for 3PM and 2PM
Ranks Player eFG%
Keeping in mind that many NBA D-League players become role players on NBA teams, it is essential that they score efficiently as they will not be high-volume shooters on NBA teams. In limited minutes, it is imperative that Call-Ups maximize their scoring opportunities and keep their teams in offensive rhythm. Of the top 10 EFG% players last season, four players got called up to the Big Show: Greg Smith (66.8%), Lester Hudson (65.3%), Terrel Harris (64.5%), Malcolm Thomas (61.9%).

Player Efficiency Rating – John Hollinger’s per-minute performance rating
Ranks Player PER
PER is the statistic with the highest correlation to the likelihood of receiving a Call-Up. Given that the statistic holistically measures a player's per-minute efficiency, it is sensible that NBA teams would value players who are positive contributors even in limited time. Of the top 13 PER players from last season, eight received Call-Ups. In fact, the players with four of the top five PERs received Call-Ups. The list includes: Lester Hudson (30.26), Terrel Harris (28.34), Eric Dawson (26.78), Manny Harris (24.55), Greg Smith (24.23), Donald Sloan (22.19), Sean Williams (22.02), Chris Wright (22.02), Andre Emmett (21.97).

Extra Credit
As you can gather, it is difficult to find one or two statistics that flawlessly predict whether or not a player will receive a Call-Up. While we discussed three statistics that have a positive correlation with Call-Up likelihood, it is worth noting, however, that there were some statistics that surprisingly did not. Perhaps most alarming of this bunch is REB% (the percentage of available rebounds a player collects). Although the player with the top REB% received a Call-Up, only six of the top 50 REB% players in the NBA D-League received Call-Ups last season and two of them already had significant NBA experience (Mikki Moore, Dan Gadzuric). Furthermore, DefRtg had an insignificant Call-Up likelihood with only five of the top 50 DefRtg players receiving a Call-Up. (Of course, DefRtg is largely dependent on the team that the player is on.) As we explore statistics throughout the year, we will refine our analysis regarding what NBA teams look for and what quantitative clues hidden in player stats indicate that a Call-Up could be around the corner.