A new VU for Duke basketball
This season, Duke became the first college basketball program to install Stats LLC’s SportVU camera system, which tracks players’ movements and provides advanced statistical data.
Getting the most out of the high-tech venture has meant tapping into the University’s high-tech experts, even if they’re not exactly who you’d expect to be assisting the basketball team.
“If you ask me the name of the Duke basketball players—I don’t know all of them,” said Guillermo Sapiro, Edmund T. Pratt, Jr. School professor of electrical and computer engineering, who is helping analyze the video.
The SportVU system utilizes six cameras in Cameron Indoor Stadium, three focusing on each half of the court. The cameras track players by identifying their jersey number, and then Stats provides an array of data—from how far a player ran during the game to a person's shooting percentage after two dribbles—to Kevin Cullen, the basketball team’s director of information technology.
Through the chair of the biomedical engineering department, Craig Henriquez, Cullen connected with Sapiro in an effort to gather even more information from the film. The first project Cullen gave Sapiro was to determine how often a player is in a defensive stance. Based on a player’s body position, Sapiro's code marks a player as standing or squatting and then places a bounding box to see how much physical space the player is taking up.
“We said, ‘Holy cow, we get to work with some of the best professors in behavioral economics or biomedical engineering in the world, and they want to take a look at this data,'” Cullen said. “This isn’t even something that Stats and SportVU have even looked at.”
Duke is still in the early stages of processing all the SportVU data. Unlike NBA teams, which play 82-game seasons with every stadium outfitted with the technology, the college season is shorter and most road venues don’t have the cameras. To gather more information, the Blue Devils became the first team, professional or collegiate, to install the cameras in its practice facility.
Because most college venues don’t have SportVU, Duke mainly uses the information for self-scouting, Cullen said. Of the team’s 14 different ACC opponents, it only plays Georgia Tech and Wake Forest at Cameron Indoor Stadium before playing them on the road, and a single game’s worth of data might not be significant.
Louisville, which joins the ACC next season, implemented the SportVU system after it had seen Duke using it, said Kenny Klein, Louisville's senior associate athletic director for media. Marquette, which plays at the same arena as the Milwaukee Bucks, is the only other college program using SportVU.
“We’re still in the discovery phase, and hopefully we discover it’s a real asset to the program,” associate head coach Steve Wojciechowski said. “The more information we can get, the better.”
The Blue Devils first became interested in the SportVU technology through a former basketball manager, Charlie Rohlf, who now works as a developer at Stats. The company then met with Duke, showing off data from the team’s NCAA tournament games, and they were sold.
Like Sapiro, Rohlf—who graduated from Duke in 2005 with a degree in computer science—is trying to help Duke by processing the data in different ways. One statistic he invented, a defensive influence score, is being tested with the Blue Devils. The metric quantifies how much a defender affects what an offensive player does.
“Duke is one of the first teams to be looking at this data at all,” Rohlf said.
But culling the data and identifying what’s significant can be a slog. For example, in the Duke games SportVU has tracked this season, which includes every home game and the ones at NBA stadiums, junior Quinn Cook has been guarded by more than 150 different players. Then Cullen and his team of students sift through it to identify useful pieces of information that he can present to the coaches. And that’s just after the fact—during every game and practice, three students have to operate the system so that the cameras communicate with one another and properly track the players.
The data helps provide ways to analyze player performance beyond typical metrics. They can see someone’s shooting percentage on catch-and-shoots or after different numbers of dribbles. The team can also get numbers on how someone shoots when he’s open versus when a defender is within two feet of him.
Instead of just seeing how many rebounds a player pulls down, they have a percentage of how often a player collects a rebound when he’s within three feet of the ball. When Amile Jefferson, a sophomore, collected a career-high 15 rebounds against Virginia last week, his real success was positioning himself to be within three feet of 20 missed shots. On the season, Jefferson grabs 65.8 percent of those rebound opportunities, the highest rate on the team for players who average at least one rebound per game.
The team also gets biomechanical information, such as how far and how fast a player runs, which Cullen said is useful for both the coaches and trainers in practice.
“People for years have said Coach K’s practices are always tougher than games, and now we’re actually getting to find out if that’s true,” Cullen said.
With less than a season’s worth of data, though, the team is just at the tip of the iceberg for fully utilizing and understanding the information. Cullen and Sapiro, who is working with two students on the project, see the potential in SportVU for behavioral analyses—for example, studying if a player’s success on offense affects what they do on the ensuing defensive possession. Sapiro has other projects that can identify where someone is looking based on a video, though he said the SportVU cameras don’t provide the necessary angles for that. He added that putting sensors in a player’s shoes or jersey could open new worlds of data.
Duke may be able to license anything Sapiro develops down the road if they want, he said, but for now he’s just happy to have Cullen’s guidance and this opportunity to collaborate with the program.
“I’m glad that Kevin and the team are willing to educate us,” Sapiro said. “If they didn’t educate us, I’d be inventing problems.”