Who Benefited from the Draft Combine?

Mar 19, 2015; Louisville, KY, USA; UCLA Bruins forward Kevon Looney (5) chases a loose ball during the first half against the Southern Methodist Mustangs in the second round of the 2015 NCAA Tournament at KFC Yum! Center. Mandatory Credit: Brian Spurlock-USA TODAY Sports

The draft combine is fascinating to me, and not for the reasons you might think. Sure, it is exciting to see athletes tested to get a better idea of their dimensions and raw athletic ability. As an amateur analyst it is exciting to reap the benefits of the data the combine generates. But I think the real fun isn’t the combine itself. It’s in the art and science of each agent or player’s decision to attend the combine.

Most years, several of the players expected to be highly drafted do not attend, despite perfect health. For potential #1 picks, this is an easy decision. Going to the combine is pure risk. The expectations are already very high. There is no pick higher than #1 and the salary for the first overall pick is predetermined. They may get injured if they participate in the combine scrimmages, especially against competition that might benefit from such an “accident”. Even without an injury, poor play or other performance could cause their stock to move, and the only direction is down.

For most players without the luxury of such a position, the decision is not as easy. Agents and players have to balance a player’s expectations, listed measurements, perceived strengths and weaknesses, actual strengths and weaknesses, current health, and market value to come to a conclusion as to whether a player should go or not.

There are default benefits to going. I’m no psychology expert, but I imagine simply being at the combine has its own benefits through some type of feature positive effect. Simply being there also shows those in attendance a player is in good health, and that he has a determination to be part of the league. These benefits must all be factored into the decision to go or not go to the combine.

So who benefitted the most from going to last weekend’s combine? In order to answer that question, it is important to understand the relationship between the combine’s measurements/tests and success in the NBA. The table below details the correlation of different combine variables from stats.nba.com with a two year career peak of a RAPM-WS blend statistic.

While most of these correlations are pretty weak, they align perfectly with common sense. If a player is taller, longer, jumps higher, runs quicker, and weighs more but has a smaller percentage of body fat, he is more likely to succeed in the NBA. Obviously. Please also note that these correlations are apples and oranges comparisons. Correlations among a smaller amount of records have more opportunity to be stronger.

Since a lot draft prospects don’t go to the draft combine, those who make draft models have to account for these missing values in some way. Without getting into the details of my draft model (which I hope to discuss more in the coming weeks), the way I solve this missing data issue when predicting the success of draft prospects is by using various models based on the measurements and performance of past combine participants to impute the missing values for prospects who don’t  attend. These models and their predictions are, at the least, an objective way to define baselines for each player’s tests and measurements.

Here is a table detailing how each player would be expected to perform, based on the draft combine participants of similar height and weight that came before him.

And here is a table detailing how each player actually performed.

There’s only so many spots in the NBA, and where some will benefit, others will fall. Below are a few of the players who, at least analytically, were significantly helped or hurt by attending the 2015 NBA draft combine. I can’t really speak to success in interviews, who “ran with grace”, or to how well scouts thought players played in scrimmages. Please view this only in the context of measurements and athletic testing.

Winners:

Justin Anderson

Justin Anderson did himself plenty of favors at the draft combine. He was taller than listed, slightly heavier but with 3.25% less body fat than you expect from players of his dimensions, and posted an above average wingspan for his height. He also registered monster standing and max verticals of 38 and 43 inches, and better than expected times in all three agility tests. For context, 38 inches is the best registered standing vertical leap since Harrison Barnes did it in 2012-2013. His athleticism was on full display.

Kevon Looney

Kevon Looney showed off arms that span 2.5 inches longer than the average wingspan for a player of his height and also registered hands that, at 9.5 inches, were tied for the second longest of the combine. Then he left before doing any damage to his increased draft stock.

Robert Upshaw

Speaking of large hands, Robert Upshaw has some. Upshaw showed up with hands that have a combined length and width equal to Kawhi Leonard’s 2011 measurements, and posted a wingspan of 89.5 inches, the largest of the 2015 draft combine.

Pat Connaughton

Although Pat Connaughton registered a strangely small standing reach given his height and wingspan measurements, (low set shoulders maybe?), he posted a monster 37.5 vertical, much higher than a previously recorded standing vertical of 32.5 at the Portsmouth Tournament. He also posted the highest max vertical of the combine, at 44 inches.

Losers:

Quinn Cook

Quinn Cook’s wingspan measured below average for his height, and he tied Ryan Boatright for the second smallest hands at the event. Unlike Boatright, who posted impressive vertical results, Cook posted a very pedestrian maximum vertical of 31 inches, and beat out only the 265 pounds of Dakari Johnson at the standing vertical leap when he jumped only 24.5 inches. On a side note, Cook also tied Tyus Jones for the second biggest difference between height with shoes and height without at the event. This isn’t really a fault, in fact, I appreciate the gamesmanship.

T.J. McConnell

Unfortunately, T.J. McConnell is very small. He registered the smallest hands at the combine, a well below average wingspan, and by the biggest difference between his expected standing reach and his actual standing reach.

Stanley Johnson

Stanley Johnson revealed himself to be 6’6.5” with shoes, when five different events since 2013 (who all had an interest in exaggerating his height) had measured him as between 6’7” and 6’8”.

I’ll leave you to decide the rest for yourselves. Overall, however, there were more dramatic winners than dramatic losers, which leads me to conclude that agents and players alike did a good job on deciding whether or not to attend.