Category: Stats and Stuff
If stats never lie, then SportVU player tracking data ought to be the keepers of truth.
Thanks to NBA.com/Stats, some data that were only accessible by NBA teams subscribing to STATS’ SportVU are now available to the public. Per its website, SportVU’s data revolve around four essential measures: speed, distance, player separation and ball possession. These are collected by six cameras — mounted to each arena’s catwalks — that track player and ball movements 25 times every second, according to NBA.com.
In short, the system collects and synthesizes endless advanced statistical measures. The Bucks are no strangers to SportVU; as early as 2011, they were one of the first 10 NBA teams to implement the system. Now, all 30 teams utilize the service following a summer agreement between STATS and the NBA. The degree to which teams actually implement the data into game preparation or roster evaluation is largely unknown. Grantland’s Zach Lowe detailed an interesting tension between the Toronto Raptors’ players, coaches, front office and analytics team on the data’s practicality.
Regardless, groundbreaking data is now available for public consumption, so I dug in to find some early-season trends. Do note, however, that the Bucks have only played seven games — or 8.5 percent of their season — and the site‘s data is not yet updated to include Milwaukee’s last game against the Magic. This is a friendly sample size warning.
(Lastly, if you want an excellent primer on the most intriguing SportVU stats, what they mean and why they are important, venture over to Bucks.com for Alex Boeder’s recent piece.)
1. Nate Wolters is tied for the league lead in secondary assists (popularized as “hockey assists”).
NBA/SportVU definition: “Quantity of passes made by a player to the player who earned an assist on a made shot. Assister must make a pass within [two] seconds and [one] dribble for passer to earn a secondary assist.”
Why this may or may not matter: First, it’s always a positive sign to be among the elite point guard company of Chris Paul and Tony Parker. It also means Wolters is passing the ball. (Indeed, Wolters is passing the ball 62.7 times per game — 11th in the league. Isn’t SportVU fun?) Ideally, he would be racking up these secondary assists with preemptive court vision — being one step ahead of the defense.
But there are always outside factors inflating or deflating assist numbers. Players on the receiving end of a pass must convert the shot for a standard assist. If a player is surrounded by great spot-up shooters and slashers, assist numbers may overrepresent his or her passing prowess — and vice versa. (I’m not sure that’s the case with the Bucks, but they do have plenty of solid spot-up shooters.) Secondary assists add another variable to an already cautious measure of passing talent.
2. Wolters ranks 19th in touches per game (76.2) and tied for 12th in time of possession (6.0 minutes).
NBA/SportVU definitions: “The number of times a player touches and possesses the ball”; “The total amount of time a player possesses the ball per game in minutes.”
Why this may or may not matter: Basically, Wolters is playing a ton of minutes — mostly by necessity, but also because of surprising competence — and that is reflected in these stats. The “touches per game” stat is largely irrelevant because of his position. However, it’s pretty incredible that Wolters is averaging less than one turnover per game despite the ball being in his hands for literally six full minutes each game.
3. Wolters is shooting 21.4 percent on drives.
NBA/SportVU definition: “The field goal percentage of a player on his drives to the basket.”
Why this may or may not matter: Here’s a reminder to temper expectations for the second-round pick. While Wolters has shown incredible ball control and awareness for a rookie, he is struggling to score efficiently. His 21.4 percent field goal percentage on drives is the 10th worst of any player who has scored at least once on a drive. His 3.8 drives per game is also relatively low number, considering he’s playing over 30 minutes per game. John Wall, who is also struggling to convert on drives (21.1 field goal percentage), is still driving 5.3 times per game.
Wolters’ jump shot hasn’t saved him, either. He’s 1-10 on spot-up opportunities, nine of which came from behind the arc, according to Synergy Sports.
Oh, and who leads the league in drives per game? Monta Ellis. He’s shooting 48.8 percent on 11.5 drives per game — good for a league-leading 8.9 points per game on drives. Who else ranks in the top ten in drives per game? Brandon Jennings, who is shooting 40.7 percent on 8.2 drives per game. I wonder what they could do together?
4. Zaza Pachulia ranks seventh in elbow touches per game (10.o).
NBA/SportVU definition: “Touches that originate within the 5 foot radius nearing the edge of the lane and free throw line, inside the 3-point line.”
Why this may or may not matter: This is in part a product of Pachulia’s extended minutes due to frontcourt injuries. Nonetheless, he’s getting the same number of touches on the elbow as the likes of Pau Gasol, Tim Duncan and David West, all of whom feast from the elbow. Pachulia is significantly less skilled than those three players, but his ability to occasionally hit a midrange jumper has allowed John Henson to work freely in the post. He and Wolters have also displayed decent chemistry on pick-and-pops.
5. Pachulia is allowing 3.4 opponent field goals at the rim per game (tied for 26th highest in NBA).
NBA/SportVU definition: “Field Goals Made by an opposing player or team at the rim while being defended.”
Why this may or may not matter: Pachulia is not a great rim protector, and opponents are not afraid to attack him. According to teammate Caron Butler, “He can’t jump over a sheet of paper but he knows how to use his body.” His imposing body hasn’t been very effective, however — opponents are shooting 54.8 percent at the rim against him. By comparison, opponents are shooting just 44.4 percent and 33.8 percent at the rim against Andrew Bogut and Roy Hibbert, respectively. Perennial DPOY candidate Serge Ibaka is allowing a Pachulia-esque 56.9 percent conversion rate at the rim. (Blocked shots must really enthrall voters.)
For what it’s worth, Ekpe Udoh and John Henson are allowing opponents to shoot 36.8 and 45.2 percent at the rim, respectively.
6. Udoh is converting on just 48.1 percent of his rebounding chances.
NBA/SportVU definition: “Measures the number of rebounds a player recovers compared to the number of rebounding chances.”
Why this may or may not matter: Udoh’s percentage of rebounds per chance (there has to be a better way to word this) ranks 318th out of 397 players. That is not good. As a measuring stick, Dwight Howard is converting 68.7 percent of his rebounding chances. But Udoh has always been a terrible individual rebounder. There’s nothing new to see here.
Henson and Pachulia are converting 62.1 percent and 52.6 percent of rebounding chances, respectively. Miroslav Raduljica successfully snagged a rebound in all of his two opportunities. Free Miroslav.
7. Gary Neal is shooting 66.7 percent on catch-and-shoot opportunities
NBA.com/SportVU definition: “The percentage of [catch-and-shoot] field goals that a player makes.”
Why this may or may not matter: Neal likes to shoot. So far, it’s working. Neal’s 66.7 field goal percentage on 2.4 catch-and-shoot opportunities per game is tied for second highest in the league (minimum of two attempts per game). Obviously, that percentage will drop with a larger sample size, but it’s currently higher than Stephen Curry’s 58.3 catch-and-shoot percentage. Revel in that for now.
O.J. Mayo and Caron Butler also like to shoot. However, Butler is converting on just 35.5 percent of catch-and-shoot opportunities. Mayo has had more success, hitting 56.3 percent of catch-and-shoot threes — tied for 18th in the NBA — on 2.7 attempts per game.
Unsurprisingly, Neal is having less success on pull-up shot attempts. Although his 8.8 points per game on pull-up shots rank fifth in the NBA, he’s shooting 40.4 percent on those attempts.
Have you noticed any other trends this season? Sift through some SportVU data and let us know in the comments.