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NBA AM: How to Measure Individual Defense

It’s hard to quantify a player’s defensive impact, but some metrics are better than others at measuring value.

Ben Dowsett

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Decoding offensive performance on the individual level has always been exponentially easier than doing so on the defensive end of the court. There are just so many more available benchmarks for offense such as points, assists, shooting percentages and numerous other extremely simple ways of quantifying a player’s value on the floor. Even just using our eyes, it’s typically far easier to watch an offensive play and immediately determine who did a good thing or a bad thing than it is to make the same assessment on the other end.

Accurate judgements of defenders on an individual basis are still possible, but they require a bit more legwork and, more importantly, an understanding of just how complex NBA defense can be. Assigning praise and blame can be such an indirect and imprecise process on this end of the floor, where all five guys have to work together and a damning mistake can happen far away from the ball. But it’s better to try than not, right? Let’s take a look at a few of the best available ways to track defensive value and performance.

The Basics:

The very lowest hanging fruit in these conversations comes in the form of the only two box score figures that are directly obtained while playing defense: steals and blocks. There’s certainly some broad, raw value to these numbers, and the league leaders will often feature some of the game’s better defenders.

With that said, their true uses are very limited; they capture just one small piece of what makes a good defender, and it’s very easy for players to excel at one or both of these particular skills despite sub-par play in many other vital areas. For example, a guy who gambles too often and jumps passing lanes all game long will rack up gaudy steal numbers, but is hurting his team in the long run due to all the possessions when he misses and ends up out of position.

Defensive rebounding is separated from the overall conversation by some, but certainly ties in and has some predictive value for defenders. Players who are best at keeping the opponent from rebounding their own misses (and therefore gaining extra chances to score) will naturally have value to a team’s defense, even if it’s indirect in many eyes.

Plus-Minus Metrics:

We discussed various plus-minus measures a couple months back, and they have some merit as indicators of an individual’s gross impact on his team on both ends of the floor. A specific variation’s effectiveness can vary wildly based on the inputs it uses and what it attempts to track. Stats like Defensive Win Shares are considered virtually useless among real statisticians; at the other end of the spectrum, Defensive Real Plus-Minus figures are, while far from perfect, a reasonably solid proxy for the value a given player adds or subtracts while on the floor. Even Real Plus-Minus and similar metrics should absolutely never be used as end-all rankings though, especially defensively. At best, they’re solid proxies with plenty of noise.

Another related variation of plus-minus figures are simple on/off court numbers, tracked in detail on NBA.com. These are what they sound like: A straightforward way to view a team’s performance with a given player on or off the floor. The league’s site allows for numerous areas of observation, from simple point differentials to detailed scoring, rebounding, passing and opponent data while a particular individual plays or sits. One of the simplest and most useful is points per-100-possessions. The Golden State Warriors, for instance, allow 95.3 points per-100-possessions while Draymond Green is on the floor (an excellent figure), but yield a yucky 108.4 when he hits the bench.

All these variations have necessary context involved, just like virtually everything in this piece. On/off figures are often incredibly noisy, unable to account for simple considerations like teammate and opponent lineup configurations. Sample sizes can be a hindrance with some players. RPM and other more detailed metrics do a decent job of controlling for some of these factors, but even the most detailed of them remains imprecise for concretely rating players on more than a broad scale.

Player Tracking:

Various player tracking systems have grown in popularity and availability in recent years, and represent the most advanced format available for measuring defensive performance. They’re the most detailed numbers out there and examine granular elements of the game in ways broader metrics simply can’t.

Tracking from Synergy Sports makes the list, though the defensive sections of their publicly available data on NBA.com are honestly pretty limited and should be taken with a hefty grain of salt in many areas. Synergy breaks the game down into play types – pick-and-roll, post up, transition, isolation, etc. Players and teams are tracked for various statistics within these play types, on both ends of the floor.

This service can be enormously valuable in many areas, but the vast majority of these are on the offensive side of the ball. The same issues as always with tracking defense arise even for such detailed services: How do you assign “responsibility” on a play where several defenders were involved and may have had some level of fault simultaneously? If a guard blows by his man on the perimeter and beats a slow help man to the rim for a dunk, which defender takes the blame? A perfect world gives some to both, but even the most advanced publicly available services don’t operate this way.

Synergy’s proprietary client (used by nearly every team in the league) offers both accompanying video and further levels of detail to all their figures, but the public stuff is limited. A keen eye to which areas are more robust is helpful – defensive figures in the post or on isolation are typically pretty clean and worth gleaning real insight from, where areas like pick-and-roll coverage or “defense” on spot-up shooters are so noisy that they should virtually be ignored altogether. Frankly, this page on NBA.com should come with a “Use With Caution” disclaimer.

A distant cousin to Synergy data is that of Vantage Sports, a site that utilizes similar tracking through a very different eventual lens. Vantage tracks even more granular data – things like screen navigation success rate and detailed levels of shot contests, minutiae that often more directly impacts the scoreboard. Vantage runs into some of the same tracking issues as Synergy, though, and in fact likely has far more trouble with accuracy within their metrics. Combine this with the fact that it’s a proprietary, non-public service, and it’s not worthy of much consideration for anyone but hardcore basketball junkies.

And finally, of course, there’s SportVU player tracking based on camera-recorded data tracked multiple times per second in every arena in the league. For one with an unlimited budget and access to proprietary data, this is far and away the most comprehensive way to determine defensive value on an individual and team basis. The full SportVU tracking database contains the maximum number of data points available to the game of basketball given modern technology.

Here’s the problem: No one in the public sphere has an unlimited budget or access to proprietary team data (more than an occasional sneak peak, at least). That’s not to say the bits we’re privy to are useless, or anywhere close. Publicly available SportVU data has increased in quantity on NBA.com each of the past three seasons including this one, and can be enormously valuable. It was recently announced that more media outlets will be given access to SportVU data in the near future, which means more data should trickle down to the public as well.

The most useful within the defensive sphere is SportVU rim protection data, which tracks how efficiently opponents score within five feet of the basket while a given player is defending it. The raw percentages allowed are informative enough, but the folks over at Nylon Calculus have taken it even further and currently house a list of the league’s best rim protectors based on “value saved” at the rim compared with league average.

There are other useful defensive elements within public SportVU data, but one needs a careful eye for them. SportVU has detailed rebounding figures that go a long way toward separating the “best” guys on the glass from the lucky ones, data that once again is housed in an even more informative manner on Nylon Calculus. NBA.com also now lists opposing field goal percentages allowed from every area of the floor, not just at the rim. Frankly, this data is pretty unreliable and should largely be avoided unless it’s complementary evidence that supports several other more robust metrics. There’s just way too much noise involved in determining whether the player physically closest to a shooter is always “responsible” for the result of his shot, and these figures alone are an easy way to incorrectly characterize a defender.

All of the above are useful and pragmatic ways to try and untangle the web of understanding NBA defense, but one disclaimer for finality’s sake: None of the publicly available data currently out there can give us 100 percent of the picture. Not even close. There’s simply too much going on to parse it all with concrete results – too many variables at play, too many pieces on the chessboard. Shoot, even the NBA GMs with access to the full SportVU data set – and therefore literally every single movement of every player at every moment on the court – would say that while it’s leaps and bounds better than anything that’s previously been available, it still has its flaws.

But isn’t that part of what keeps basketball so fun? The fact that we can’t know everything about a particular part of the game is what makes debates about it so entertaining. Would we even want a metric that solved NBA defense? No. We’ll always chase a higher level of understanding, and the metrics in this piece are a guide, but the magic of the game is the stuff we’ll never figure out.

*****

Listen to the latest episode of the Basketball Insiders podcast, in which Moke Hamilton and Ben Dowsett discuss their All-Star selections, the race for the eighth seed in each conference and the 12-man Olympic roster.

Ben Dowsett is a Deputy Editor and in-depth basketball analyst based in Salt Lake City. He covers the Jazz on a credentialed basis for Basketball Insiders, and has previously appeared in the Sports Illustrated and TrueHoop Networks. He can be found on Twitter at @Ben_Dowsett.

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NBA DAILY

NBA Daily: Pelicans Might Be Better Off Without DeMarcus Cousins

Without DeMarcus Cousins, Anthony Davis has excelled. It might not be a coincidence.

Moke Hamilton

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Forget Kawhi Leonard, the most interesting storyline of this NBA summer is going to be DeMarcus Cousins.

By now, if you’ve wondered whether the New Orleans Pelicans would be better off without the talented big man, you’re certainly not alone.

Just ask the Portland Trail Blazers.

On Saturday, the Pelicans pulled off an improbable sweep of the third-seeded Blazers in the first round of their best-of-seven playoff series. And while the immediate question that comes to mind is what to make of the Blazers, a similar question can be (and should be) asked of the Pelicans.

Without question, Cousins is one of the most gifted big men the NBA has sen in quite some time, but it shouldn’t be lost on any of us that Anthony Davis began to put forth superhuman efforts when Cousins was absent.

Ever heard the saying that too many cooks spoil the brew?

That may be pricisely the case here.

Sure, having good players at your disposal is a problem that most head coach in the league would sign up for, but it takes a special type of player to willingly cede touches and shots in the name of the best interests of the team.

We once had a similar conversation about Russell Westbrook and Kevin Durant, mind you. Those that recognized that Westbrook’s ball dominance and inefficiency took opportunities away from Durant to be the best version of himself once believed that the Oklahoma City Thunder would have been wise to pitch Westbrook to New Orleans back when Chris Paul was still manning their perimeter.

For what it’s worth, with Cousins in the lineup, he averaged 18 shots per game. In the 48 games he played this season, the Pelicans were 27-21. With him in the lineup, Davis shot the ball 17.6 times per game and scored 26.5 points per contest.

In the 34 games the Pelicans played without Cousins, Davis’ shot attempts increased fairly significantly. He got 21.9 attempts per contest and similarly increased his scoring output to 30.2 points per game.

Aside from that, Cousins’ presence in the middle made it a tad more difficult for Rajon Rondo and Jrue Holiday to have the pace and space they need to be most effective. With both Davis and Cousins, the Pelicans struggled to consistently string together wins. Without Cousins, they improbably became the first team in the Western Conference to advance to the second round.

That Cousins tore his achilles tendon and is just a few months from becoming an unrestricted free agent combine to make him the most interesting man in the NBA.

* * * * * *

With Chris Paul having decided that the grass was probably greener with James Harden and Mike D’Antoni than it was with Doc Rivers and Blake Griffin, the Clippers fulfilled his request to be trade to the Houston Rockets and re-signed Griffin to a five-year max. deal. In doing so, they both gave Griffin a stark reminder of what life in the NBA is like and provided a blueprint for teams to follow when they have a superstar player with whom they believe to have run their course.

The glass half full perspective might be that Davis has simply become a better, healthier, more effective player and that with Cousins, he would have another weapon that could help catapult the Pelicans ever further toward the top of the Western Conference. But the half-empty glass might yield another conclusion.

At the end of the day, although he still hasn’t appeared in a single playoff game, Cousins is regarded as a game-changing talent and is one of the few players available on the free agency market this summer that could justify an annual average salary of $30 million. In all likelihood, the Pelicans will re-sign him for a sum that approaches that, but that doesn’t mean it’s the best move.

In the end, the Clippers traded Griffin for Avery Bradley, Tobias Harris, Boban Marjanovic, a first round pick and a second round pick. All things considered, it was a great haul for the Clippers when you consider that, just a few months prior, they could have lost Griffin as a free agent and gotten nothing in return.

Remarkably, after seeing Griffin dealt to Detroit, in the Western Conference, the Pelicans are on a collision course with the Golden State Warriors. Their health a constant concern, the team will have to deal with the pesky perimeter defense of Holiday and Rondo and versatility and two-way effectiveness of Davis.

Nobody gave New Orleans a chance against Portland, and for sure, not many people are going to believe in their ability to score an upset over the defending champions. But believe it or not, New Orleans has become a different team. And they’ve done so without Cousins.

Indeed, believe it or not, the Clippers gave us a blueprint for what a team should do when it has a superstar who might not be the best long-term fit for their program.

And if the Pelicans were wise, they’d be smart to follow it.

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NBA Daily: Rookie Contributors Lifting Playoff Teams

This year’s impressive rookie class has translated their regular season performances to the playoff stage.

Dennis Chambers

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This past NBA season had the luxury of an incredibly entertaining and high-powered rookie class. Every other day it seemed like the feats of either Donovan Mitchell, Jayson Tatum, Lauri Markkanen, Dennis Smith Jr., Kyle Kuzma, or Ben Simmons were dominating the discussion about how advanced the league’s crop of newbies appeared to be.

As a result, the 2017-18 Rookie of the Year race was a much more heated discussion than the year before.

With the impressive campaign these NBA freshmen put together, it should come as no surprise that on the on bright stage of playoff basketball, three of the aforementioned crop are helping lead their team’s in tight first-round battles.

Donovan Mitchell has been the leading scorer for the Utah Jazz through two games in their series against the Oklahoma City Thunder. Jayson Tatum is stepping up for the Boston Celtics to help fill in the void of Kyrie Irving as they take on the Milwaukee Bucks. Ben Simmons is nearly averaging a triple-double through three games for the Philadelphia 76ers in their matchup with the Miami HEAT.

Lottery pick talents are expected in today’s NBA to come in and have some level of impact for their clubs. Usually, they play the role as a foundational building block that shows flashes of promise with an expected up-and-down first season. While these three playoff contributors haven’t been perfect all year long, under the pressure of the postseason, they’ve stepped up their play and appear to be avoiding the learning curve.

With that, let’s highlight further what Mitchell, Tatum, and Simmons have been able to do thus far in the postseason.

Donovan Mitchell, Utah Jazz

All season long Mitchell threw the entire scoring load of Salt Lake City on his back for the Jazz and helped carry them to a 5-seed in the Western Conference when early season projections suggested they should head towards in the wake of Rudy Gobert’s injury.

However, the 13th pick out of Louisville had no intentions of missing out on the postseason. And from the looks of his production so far, who can blame him?

Through the first two games of the Jazz-Thunder series, Mitchell yet again placed his name in the same breath as Michael Jordan. Mitchell’s 55 points in his first two playoff games broke Jordan’s record of 53 for most points scored by a rookie guard in that scenario.

Mitchell’s 27 points in Game 1 and 28 points in Game 2 led the Jazz to even the series and steal home court advantage from the Thunder. While he hasn’t been responsible for setting up the team’s offense, tallying just five assists through those two games, Mitchell is fulfilling the role of Gordon Hayward as the team’s primary scorer.

In a series against a team that features the likes of Russell Westbrook, Paul George, and Carmelo Anthony, Utah needs Mitchell to go out there and get as many buckets as he possibly can.

So far, he appears to be welcoming the challenge.

Jayson Tatum, Boston Celtics

When it was announced that Kyrie Irving would be lost for the entire postseason due to injury, the Boston Celtics’ hold on the 2-seed seemed a lot less intimidating than it once was in the Eastern Conference.

However, three games into the first round series against the Bucks, the Celtics hold a 2-1 lead. A lot part of that has to do with the role Tatum has been able to step in and play right away with the Celtics down their main scorer and playmaker.

Throughout the first three games of the series, Tatum 12.3 points, 7.3 rebounds, 2.3 assists, and 2.3 steals. The third overall pick in the 2017 draft started the series off with 19 points, 10 rebounds, and three steals to help Boston start off the matchup with a 1-0 lead.

At just 20 years old, Tatum is matching his age number with his usage percentage thus far against Milwaukee. For some perspective, Jaylen Brown managed just 12 minutes a night for the Celtics last season as a rookie when the playoffs rolled around.

Granted, injuries and missing players are helping in Tatum being on the court as much as he has, but the rookie is earning his time out there on the court.

Ben Simmons, Philadelphia 76ers

The perceived frontrunner for Rookie of the Year, Ben Simmons has taken control in his first ever playoff series.

For starters, Simmons is averaging nearly a triple double over his first three games against the HEAT; 20 points, 10 rebounds, and 9.7 assists.

On top of his triple double ways, Simmons has upped arguably his biggest weakness so far in the playoffs, shooting 75 percent from the charity stripe. During the regular season, Simmons struggled from the line, hitting only 56 percent of his attempts.

With the offensive prowess of Simmons obvious, it’s the job he’s doing on the defensive end of the court against an aggressive and tough Miami squad that’s elevating his play to the next level.

Simmons’ ability to switch all over the defensive end of the court has placed his responsibilities from Goran Dragic to Justise Winslow to James Johnson, and seemingly everywhere in between.

Now with Joel Embiid back in the fold for the Sixers and Simmons, the rookie point guard has his defensive partner on the floor to help ease the workload on that end. A two-way performance each night will be imperative for Simmons in helping lead the young Sixers past the experienced HEAT team.

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Pelicans Role Players are Key to Success

The supporting cast in New Orleans is a big part of their playoff surge, writes David Yapkowitz.

David Yapkowitz

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The New Orleans Pelicans have taken a commanding 3-0 lead in their first-round playoff series again the Portland Trail Blazers. While surprising to some, the Pelicans only finished one game behind the Blazers in the standings. The Pelicans have the best player in the series in Anthony Davis and the defensive duo of Rajon Rondo and Jrue Holiday have stifled Portland’s backcourt.

The truth is, the Pelicans have been a good team all season long. A lot of attention and recognition has been given to Davis, Rondo and Holiday this season and playoffs, and rightfully so. But New Orleans wouldn’t be where they are without the important contributions of some of their role players.

Take E’Twaun Moore, for example. Moore bounced around the NBA early in his career, with stops in Boston, Orlando and Chicago before finding long-term stability contract wise with the Pelicans. He’s primarily been a bench player with them before this season, his second in New Orleans, his first as a full-time starter.

He’s given the Pelicans a huge boost, especially from the three-point line. He’s put up 12.5 points per game on 50.8 percent shooting from the field, both career-highs. He’s shooting 42.5 percent from three-point range.

“I think it’s just our style of play,” Moore told Basketball Insiders. “We play fast and open. Coach [Gentry] gives us a lot of freedom, a lot of confidence. That’s why my game is up, my shooting is up.”

It’s not just offensively though. Moore has always been one of the more underrated defensive guards in the league. Paired up alongside Rondo and Holiday, the trio form a solid wing defensive unit. They’re a big reason for Portland’s offensive struggles.

Moore is the type of role player that every playoff contender needs to succeed. He knows that his role may change from game to game. Some nights he may be asked to score a little more. Other nights his defense is going to be called upon. Whatever it may be, he’s always ready to do what’s asked of him.

“I bring the energy. I bring a spark,” Moore told Basketball Insiders. “It’s knocking down shots, playing defense, getting out in transition. Just trying to be a spark.”

The Pelicans bench has also been a huge factor all season long. Their depth took a major hit early in the season with the injury to Solomon Hill. Hill has since returned to the lineup, but his absence paved the way for other players such as Darius Miller to step up.

This is Miller’s second stint with the Pelicans after spending two years overseas. Drafted 46th overall in 2012, he didn’t play much his first three years in the NBA. In 2014, he was cut by the Pelicans only about a month into the season. This year was different, he was thrown into the rotation from the get-go.

“This is a huge opportunity,” Miller told Basketball Insiders. “I just come in and try to work every day, try to get better every day. My teammates have done a great job of putting me in situations where I can be successful.”

Miller has given the Pelicans a capable stretch four in the second unit who can slide over to small forward if need be. He’s averaging a career-best 7.8 points per game, the most out of any of New Orleans’ reserves. He’s their best three-point shooter off the bench, connecting on 41.1 percent of his long-range attempts.

While he acknowledges that he’s enjoying his best season yet as an NBA player, he’s quick to praise his teammates for allowing him to flourish.

“I just try to bring a spark off the bench. I come in and try to knock some shots down,” Miller told Basketball Insiders. “My teammates do a great job of finding me when I’m open, I just try and knock down shots and compete.”

Sometimes time away from the NBA helps players grow and mature. The NBA game is fast paced and it can take awhile to get used to it. While some players have begun to use the G-League as a means of preparing for the league, Miller took an alternate route of heading to Germany.

For him, it’s a big reason why he’s been able to make an easier transition back to the NBA. His contract for next season is non-guaranteed, but he’s probably done enough to warrant the Pelicans keeping him around. He’s a much different and much-improved player. If not, he’s sure to draw interest from other teams.

“It was a lot to learn for me personally,” Miller told Basketball Insiders. “I had to learn a lot of different things like how to take care of my body, how to manage my time, a whole bunch of stuff like that. The time overseas really helped me to mature and grow up and learn a few things.”

These Pelicans have most certainly turned quite a few heads since the playoffs began. We shouldn’t deal too much with hypotheticals, but it’s interesting to wonder what this team’s ceiling would’ve been had DeMarcus Cousins not been lost for the season due to injury.

This is a confident bunch, however. They’ve beaten both the Golden State Warriors and Houston Rockets during the regular season. They’ve already shattered a lot of expert predictions with their performance in the first-round. The Pelicans feel like they can hang with anyone out West.

“As far as we want to go,” Miller told Basketball Insiders. “I feel like we’ve competed with all the best teams in the league this whole season. We just got to come out, stay focused and do what we do.”

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