Last night, the NBA held its annual draft. The NBA draft is often a time for colleges to extol the success of their programs based on the number of draft picks they have produced. Fans and programs seem to be primarily focused on the output of the draft. Our take is a bit different, as we examine the process of taking high school talent and converting it into NBA draft picks. In other words, we want to understand how efficient are colleges at transforming their available high school talent into NBA draft picks? Today, we present our second annual ranking of schools based on their ability to convert talent into draft picks.
Our approach is fairly simple. Each year, (almost) every basketball program has an incoming freshman class. The players in the class have been evaluated by several national recruiting/ranking companies (e.g. Rivals, Scout, etc…). In theory, these evaluations provide a measure of the player’s talent or quality*. Each year, we also observe which players get drafted by the NBA. Thus, we can measure conversion rates over time for each college. Conversion rates may be indicative of the school’s ability to coach-up talent, to identify talent, or to invest in players. These rates may also depend on the talent composition of all of the players on the team. This last factor is particularly important from a recruiting standpoint. Should players flock to places that other highly ranked players have selected? Should they look for places where they have a higher probability of getting on the court quickly? Last year, we conducted a statistical analysis (logistic regression) that included multiple factors (quality of other recruits, team winning rates, tournament success, investment in the basketball program, etc…). But today, we will just present simple statistics related to school’s ability to produce output (NBA draft picks) as a function of input (quality of recruits).
Here are some questions you probably have about our methodology:
What time period does this represent?
We examined recruiting classes from 2002 to 2013 (this represents the year of graduation from high school), and NBA drafts from 2006 to 2014. We compiled data for over 300 Division 1 colleges (over 15,000 players).
How did you compute the conversion rate?
The conversion rate for each school is defined as (Sum of draft picks for the 2006-2014 NBA Drafts)/(Weighted Recruiting Talent). Weighted Recruiting Talent is determined by summing the recruiting “points” for each class. These “points” are computed by weighting each recruit by the overall population average probability of being drafted for recruits at that corresponding talent level. We are trying to control for the fact that a five-star recruit is much more likely to get drafted than a four or three-star recruit. We are using ratings data from Rivals.com. We index the conversion rate for the top school at 100.
Second-round picks often don’t even make the team. What if you only considered first round picks?
We have also computed the rates using first round picks only, please see the table below.
Mike Lewis & Manish Tripathi, Emory University 2014.
*Once again, we can already hear our friends at Duke explaining how players are rated more highly by services just because they are being recruited by Duke. We acknowledge that it is very difficult to get a true measure of a high school player’s ability. However, we also believe that over the last eight years, given all of the media exposure for high school athletes, this problem has attenuated.