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Department of Defense: A new Sloan Conference paper might be the key to unlocking our understanding of defensive basketball

Later this week, my colleagues Alexander Franks and Andrew Miller, who are both PhD students at Harvard,1 will present a research paper at the MIT Sloan Sports Analytics Conference in Boston. In conjunction with professor Luke Bornn of Harvard’s Statistics Department and myself, Franks and Miller have been researching defensive analytics in the NBA for almost two years. You can [url=]read the full paper here[/url], but here’s the elevator pitch: We are confident that we’ve developed methods that will enable analysts to more richly characterize defensive performance in the NBA.

Measuring defense is a challenging endeavor, and the behaviors of truly great defenders don’t fit nicely into the cells of spreadsheets. Highlight culture rewards individual offensive achievement, while the defenders in those clips are largely reduced to the same status as officials. If they do their jobs, people don’t even notice they’re there. (Unless we’re talking about Brandon Knight.) As a result, defensive reputations remain murky, and with a few exceptions — Zach Lowe’s wonderful article about the Raptors from two years ago, Ethan Sherwood Strauss’s look at the making of the Warriors defense — meaningful defensive analyses are rare.

In the summer of 2013, the NBA installed player-tracking systems in all 29 of its arenas. Every seemingly mundane action on the court would now be catalogued — from distance run to dribbles taken. But the massive new data set offered something else much juicier: the chance to finally analyze every second of defense played in every arena in the NBA.

It’s all in the little blue lines:


I don’t know enough about the NBA to know whether any of the examples confound eyeballs’ views, but here is Kawhi Leonard’s impressive defensive chart:

And these interior defenders:

The James Harden defensive shot chart. Wow!!!

To be fair, the eyeball notion has been that James Harden’s defense has drastically improved this season. Granted, we’ll see on his defensive chart I’m guessing some time in the summer.

I continue to love Charles.

Not Penn State, but I have been assuming we did this when I talk about the Moore-Dickerson +/- - but who knows:

But when Tim Chartier, a professor in Davidson’s mathematics and computer science department, approached the coaching staff with an idea, there was uncertainty that the unorthodox partnership would pan out.

Chartier and his students presented a way to show the efficiency of every five-man lineup that Davidson used in games. As Chartier explained, a player may not produce individual statistics that indicate he is making an important contribution on the court, but by looking at the players in a group, their role becomes clearer.

“It kind of blew us away,” Matt McKillop said, “and when they explained the way we could look at lineups and see how we were most efficient offensively and defensively, it really opened our eyes up to the possibility.”

I really hope our guys have access to this kind of stuff. If Synergy is what it takes, I hope the AD ponies up. (Would be hard to imagine the football team wouldn’t get this kind of thing.)

How good a marginal rebounder are you really?

[quote="ESPN's Bradford Doolittle"]Both the Clippers and Pistons have better defensive rebound rates with their star rebounders on the bench. How is that possible?

This is a big topic, but one possible reason could be the simple fact that neither [DeAndre] Jordan nor [Andre] Drummond is particularly concerned with boxing out…Drummond blocks out on the defensive glass just 5.97 times per 100 opportunities, lowest in the league among centers with at least 500 chances.[/quote]

Jordan is a little better at 9.64, but that’s still the 11th-lowest total.

In other words, what really matters is marginal rebounding prowess, adjusting for how many rebounds you take away from the other players on your team. Maybe an individual can pull in the ball more often by positioning himself to grab the low hanging fruit rebounds — often taking them from other team members — rather than boxing out the other team for the tough, contested rebounds.

I daresay this was one poster’s point about Ross’s amazing rebounding totals?

I coached a kid that averaged about 7 rebounds a game through his career. I swear to god, he was the king of the defensive free throw rebound from the first spot on the block. In reality, he very rarely came up with the “tough” rebound, yet he was 2nd on the team in rebounding his jr and sr. year. Looked nice on paper, but not a guy I trusted.

Like many things defensively, I’m concerned with how the overall team rebounds with certain lineups on the floor. What’s our defensive rebound rate with lineup A vs lineup B, etc.?

People used to complain a lot that Talor Battle’s teams didn’t have enough rebounds going to the bigs, but we used to have some pretty good rebounding numbers as a team in those days. I think the bigs were usually doing a great job blocking out and the guards were just cleaning up the rebounds - as we rarely looked to fast break off of misses so there was no point in keeping anybody out of the paint on an opponents shot. It worked for what we were trying to do, so I don’t think it matters who was getting the actual credit for the rebound.

Love the economist Tyler Cowen:

Stephen Curry and the duration of the great stagnation

In other words, this “technology” has been legal since 1979, yet only recently has it started to come into its own. (Some teams still haven’t figured out how to use it properly.) And what a simple technology it is: it involves only placing your feet on a different spot on the floor and then moving your arms and legs in a coordinated (one hopes) motion. The incentives of money, fame, and sex to get this right have been high from the beginning, and there are plenty of different players and teams in the NBA, not to mention college or even high school ball, to figure it out. There is plenty of objective data in basketball, most of all when it comes to scoring.

How about this for some advanced analytics: You are what your record says you are - at least in basketball:

Statistics-Free Sports Prediction

We use a simple machine learning model, logistically-weighted regularized linear least squares regression, in order to predict baseball, basketball, football, and hockey games. We do so using only the thirty-year record of which visiting teams played which home teams, on what date, and what the final score was. No real "statistics" are used. The method works best in basketball, likely because it is high-scoring and has long seasons. It works better in football and hockey than in baseball, but in baseball the predictions are closer to a theoretical optimum. The football predictions, while good, can in principle be made much better, and the hockey predictions can be made somewhat better. These findings tells us that in basketball, most statistics are subsumed by the scores of the games, whereas in baseball, football, and hockey, further study of game and player statistics is necessary to predict games as well as can be done.


ESPN: In the age of analytics, putting the focus back on scouting

Baseball, but on topic

Review of the great Michael Lewis’s new book, which apparently digests for laymen my favorite book of last decade or so, Thinking Fast and Slow (which doesn’t need digesting - read it!)

I just ordered that book (“Thinking Fast and Slow”), and it’s supposed to come tomorrow! I was having a discussion with someone last week about the stock market (he’s new to it), and I had recommended that he read “A Random Walk Down Wall Street” as a primer on investing. He, in turn, recommended “Thinking Fast and Slow,” saying that he likes to read books that smart people he knows are reading, and that was one of those books. I had forgotten which book it was that he recommended to me until I saw the title in a review of Lewis’s book. After I read that, I may have to take a run at Lewis’s book, too.

Slate actually printed a good sized section of the Michael Lewis book today, you can read here. Very nice read, going to pick up the whole book now.

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Listening to repeated declarations of “find/go to the hot hand” had me looking for more on the hot hand controversy.

This paper is good: Sloan Conference: The Hot Hand : A New Approach to an Old “Fallacy”

Finding: when adjusting for difficulty of shot, there is a hot hand. An NBA player who makes two or more of his last four shots is 2.4% more likely to make his next when controlling for shot difficulty (players who think they’ve a hot hand tend to take more difficult shots!)

In other words, a 45% shooter becomes a 46.1 percent shooter with a hot hand. So likely to make 1 more three-point shot of the next 100 than he had been previously if his shot selection is good.

To add to this, I don’t think the average basketball analyst is thinking “go to the guy likely to make one more shot than usual in the next 100!” when they urge seeking out the hot hand.

I suspect their intuition is more like “the hot-hand guy is now a 70-80% shooter”’, not “the 33-percent three-point shooter is now a 33.8% shooter - get him the darn ball!”

Moneyball ruins everything

Sports books have capitalized on big events, too. During March Madness, a five-person booth at the Harrah’s Las Vegas sports book cost $375 per person, which included five Miller Lite or Coors Light beers a person. In the past, seating at most sports books was free and first-come, first-served, even during big events. Placing a small bet or two could get you free drinks.

Ha, they got ripped off.

Spent this past March Madness opening weekend in Vegas. We did the Cosmo Hoops and Hops event, it was like 4 giant ballrooms opened up to form one big space that had HD projectors covering every wall the whole way around. There’s a video of it here to get an idea of how it looked: If you missed our exclusive college... - The Cosmopolitan of Las Vegas

It was between 150-250 a day (depending on single day vs multi day and VIP or not) and regular tickets didn’t include food, but was open bar all day and they were selling food inside the place all day with the menu changing from breakfast to lunch/dinner. You could reserve one of about 80 leather couches in the front for a bit more and be a VIP which DID include food. Othewise you could sit at high tops or giant wedding-style round tables that seated like 12 with decent enough chairs.

They had betting stations right outside the room with tv’s out there as well, never had to wait more than about 2 minutes to get a bet in if you timed it right.

I’ve been out there for MM before and tried to just get seats wherever we could find them with no real gameplan and it’s just not worth it. Having a comfortable seat with perfect views of all the screens is the way to do it, even if it’s going to cost you.

This was also one of the pricier events from what I saw, at least for general admission. But one of the best ran events as well, highly organized and very effectively managed. Was a lot of fun as well, whole place was packed but not crowded and everyone was living and dying on every point spread and total.

Missed this a couple of days ago. Wonder if Franklin does this stuff, thinking of his fourth-down tries in last year’s Big Ten championship.