SPORTVU AND U
By Grady O'Brien | November 13, 2013
Listen, you guys. I get it. I’m a nerd. I played Starcraft in high school and own more than one They Might Be Giants album. I’ve come to terms with it.
So you can only imagine how I felt when NBA.com unleashed its “player tracking” section of the stats page. For those who might not know yet, player tracking is the product of the league’s new SportVU technology. This advancement consists of six cameras installed in each NBA arena (only half of league had them last year) that track every single movement made by the players and the ball. Naturally with this tracking system comes heaps of data, the kind for which nerds like me thirst.
Since this player tracking data likely will start creeping its way into the NBA internet parlance, I thought it might be nice to do a quick survey of what we’re dealing with and how it relates to the Blazers.
As a note, I filtered results to include players who have averaged at least 15 minutes per game in at least 5 total games as to avoid crazy small samples. Still, this information is from a very limited number of games and thus will still be fluky.
Speed and Distance
This section tells us fun things like how far guys are running during a game and how quickly they do it. For soccer fans, think of the mid-game television graphics that pop up to say that Ashley Cole has run 4.5 km or whatever — it’s a pretty identical function here. Interesting, sure, but as far as real applications or what it can add to the understanding of the game, I’m uncertain. Also, the raw numbers appear to be heavily influenced by minutes played and team pace. For example, nine of the top fifteen players in total distance traveled play on the seven teams with the highest pace.
That being said, Chandler Parsons leads the league in total miles traveled at 22.4. Nic Batum has traveled the farthest for the Blazers, running 18.4 total miles, an average of 2.6 per game. Patty Mills of the Spurs is the league’s speed demon, averaging a speed of 4.9 mile per hour.
Touches and Possession
The data on touches and possessions should be useful in supplementing current stats like usage rate. Here, SportVU measures things like how many times a player touches the ball, how long they possess the ball during a game, and where their touches come from. Many of these categories are predictably dominated by point guards (and thus extra-dominated by Chris Paul), but Kevin Love has supplanted himself in the top 10 for “touches per game,” even ahead of teammate Ricky Rubio.
In unsurprising Blazer news, LaMarcus Aldridge is fourth in “elbow touches per game,” which is defined by a 5-foot radius nearing the edge of the lane and free-throw line inside of the 3-point line. LMA gets 10.9 of these touches per game (league leader Marc Gasol actually averages 16.4!).
One of the best early small-sample SportVU revelations is Michael Beasley leading the league in “points per touch.” At first it seems like maybe Beas has turned around his efficiency issues. But it could also mean that the only thing he attempts to do when possessing the ball is score. Points per touch will be a category to watch.
Passing
This is the category I was most interested to see. I’m not alone in questioning the true value of the assist stat. Yes, usually the good point guards are the ones who rack up the assists. But what of all the great passes that lead to missed shots or free throw attempts when a teammate is fouled? What of the “hockey assists” where the brilliance of a pass needs one more step to be fully realized? We needn’t fret any longer as these things are all now being recorded.
“Free throw assists” account for plays in which a pass leads to free throw attempts (where at least 1 attempt is converted) and “secondary assists” account for a pass that leads to the true assist (as long as the next pass is made within 2 seconds or 1 dribble). Russell Westbrook leads the league in free throw assists, which makes sense as he plays alongside of the foul-drawing nightmare that is Kevin Durant. The league leader in “secondary assists” is Nate Wolters and I’ll use the rest of this sentence to give you time to figure out who that is.
The last interesting part of this category is “points created by assists per game,” which accounts for the entire value of the assists a player makes by factoring in 3-pointers and free-throws. Now we can get a feel for which players’ assists actually create the most value. Nic Batum actually leads the Blazers in this category, further illustrating the visible strides he’s made as a playmaker.
Defensive Impact
Remember that time Kirk Goldsberry wrote a fascinating Sloan Sports Conference paper about why Larry Sanders was awesome at defense and David Lee probably wasn’t? Well this page is the embodiment of that article. It keeps track of the basic counting stats like steals and blocks, but it also tracks effectiveness at the rim. This is where we find out that of the 3.8 shot attempts per game that opponents take against Taj Gibson at the rim, only 21.7 percent go in, which isn’t great. Stop shooting at the rim against Taj Gibson, NBA opponents. This is also where we find out that the Blazers aren’t defending the rim particularly well. Robin Lopez sees 10.1 attempts at the rim per game and gives up 49.3 percent shooting on those chances. And he’s the best Blazer big on the list.
Rebounding Opportunities
For a long time, raw rebound totals were the measure of a player’s rebounding ability. But simple totals are very reliant on pace and opponent shooting percentage. Then rebound rate came along, which made significant improvements by adjusting for the number of rebounds available to player and pace. Now we can see how many times an individual player has the opportunity to get a rebound and whether the rebound is being contested. This will now allow us to judge who is the best at positioning themselves to be available for a board and how well they battle in traffic.
LaMarcus Aldridge sees the most rebounding chances per game for Portland at 14.4 per game. However, Joel Freeland has the highest contested rebound percentage of any Blazer, grabbing 56.5 percent of all contested rebounds he’s a part of.
Drives
This one seems pretty simple. It lets us know who is attacking the basket and how effective they are when they do so. A “drive” is defined when a touch starts out 20 feet or more from the hoop and is dribbled to within 10 feet. It does not include fast break opportunities as drives, so apologies to last year’s Denver Nuggets.
The stat I like most from this section is “team points per game on drives” which encompasses all the points a team scores from a players’ drives by factoring in assists as well. Ty Lawson leads the league with 14.8 per game. Number two is the oft-disparaged Monta Ellis. Damian Lillard does the most driving for the Blazers, but has shot a woeful 28.6 percent on his drives this year
Shooting Efficiency
The last few categories can basically be rolled into one. They measure the effectiveness of a shooter based on whether the shot was a catch-and-shoot or a pull-up opportunity. The value of this distinction is fairly self-explanatory, but nonetheless crucial. Now we can objectively know whether all those Nick Young shots are worth it (they are not).
The league leader in effective field goal percentage on pull-up shots (min. 20 such points) is rookie Ben McLemore at 80.8 percent. The leader in catch and shoot effective field goal percentage (min. 20 such points) is Mario “Rio” Chalmers at a scorching 95.5 percent. For Portland, Wes Matthews stands out in both categories, with an effective field goal percentage of 75 percent on catch-and-shoot attempts (12th best in the league) and 55 percent on pull-ups (8th best in the league).
So what have we learned?
Maybe not much yet. All this data and information is so new that it’s hard to tell how it can and should be used. Needless to say, analytics departments, scholars, serious journalists, serious bloggers, and dudes like me will spend a lot of time trying to figure it out. First, and most simply, SportVU probably will be used to enhance the understanding of traditional measurements and more clearly define the visual understanding of what’s happening on the floor. But with the amount of intelligent people inside and outside of NBA teams working deeper into its potential, it could eventually reshape the entire frame of reference for understanding the game of basketball.
Now if you’ll excuse me, I need to go blast “Birdhouse in Your Soul” and build more Supply Depots.