David Berri on Adjusted Plus/Minus

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Way back in 2006, David Berri, Martin Schmidt, and Stacey Brook came out with a book called The Wages of Wins. It was supposed to be Moneyball for sports other than baseball, but for a lot of people, the book read like Moneyball with a serious chip on its shoulder. In a team game with lots of variables, Berri and his co-authors were confident in their regression-based assertions that  there were 90 players more valuable than Allen Iverson during the season that he won MVP, that scoring was vastly overvalued while rebounding was too often neglected, and Ray Allen had been just as good throughout his career as Kobe Bryant. 

The general feeling among a lot of hard-core basketball fans and analysts was that the Wages of Wins system, which relied only on box-score based statistics, couldn’t possibly accurately capture everything that made a player valuable in a five-on-five game. The logical extreme of that philosophy came in the form of Wayne Winston, the former stat guru for the Dallas Mavericks whose brainchild was adjusted plus/minus, which sought to measure a player’s value without using any box-score statistics whatsoever. As it turned out, he had some even more outlandish conclusions than Berri and co. did. He said that the Knicks should never have traded Tim Thomas, that Lamar Odom was better than Kobe Bryant, and that Kevin Durant wasn’t helping the Thunder win. 
After last weekend’s Sloan stats and analytics conference, David Berri has a short post up on adjusted plus/minus. Here’s the crux of Berri’s argument for box-score bases metrics over adjusted plus/minus:
JC Bradbury and I – in a forthcoming article in the Journal of Sports Economics — report that only 7% of a player’s adjusted plus/minus is explained by what a player did the previous season (oddly enough, unadjusted plus/minus has a stronger – albeit still relatively weak – correlation).  In other words, the correlation coefficient for adjusted plus/minus from season-to-season is below 0.30.   And when we look at players who switch teams – as Songaila did – we fail to find a statistically significant relationship. In contrast, any measure (PERs, Wages of Wins measures, NBA Efficiency, Win Shares, etc…) based on the box score will have a correlation coefficient of at least 0.65, and often these marks are above 0.80. 

Berri makes a solid point. He uses Darius Songalia as a case study for how inconsistent adjusted plus/minus can be, but he could easily have used Kevin Durant, who started the season as a posterchild for how plus/minus based stats could contradict box score metrics but is now an example of how elastic adjusted plus/minus can be from season to season. 

I’m a big believer in using advanced stats to gain knowledge about basketball, but it appears that both Berri and Winston have holes in their metrics. Berri’s box-score based metrics don’t necessarily reflect who was doing what helped his team win the game. For example, let’s say Matt Barnes plays great defense on Kobe for 20 seconds and forces him into a tough fadeaway. Dwight Howard then blocks out Pau Gasol and keeps him from getting to the rebound. The ball caroms off the rim and goes to Vince Carter, who collects the easy rebound. In Berri’s system, only Carter gets credit for doing something right on that play. 
Winston’s system would theoretically give Barnes and Howard most of the credit for the play above. However, the issue is that they could have radically different roles on a different team. With another team, Barnes might not be a starter or a perimeter scorer, but a stretch four who provides energy and outside shooting off the bench without giving much on the defensive end. Thus, he could have a radically different value with a different team. 
Advanced statistics in basketball are wonderful, but they are far from airtight. For the foreseeable future, the best approach with advanced statistics will be to use a number of different metrics and see how they inform each other rather than wait for one perfect formula to reduce contributions to a single integer. 

Derrick White didn’t lose teeth, passes concussion test after nasty fall in USA loss

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There were plenty of ugly things for Team USA in its loss to Australia on Saturday — most of them on the defensive end — but later in the day on Saturday there was some good news.

It sounds like point guard Derrick White will be fine after his nasty fall and face plant during the game, reports Tom Osborne of the San Antonio Express-News.

In the middle of the fourth quarter, White was pushing the ball upcourt after an Australia miss and either got clipped from behind — there was a foul called — or stumbled over his own feet. I lean clipped, but the video is not conclusive.

White fell and faceplanted, with his head bouncing off the court. If he got away with just stitches, that’s good news for Team USA. If White had a concussion it is possible he would have missed the start of the World Cup, and the USA is not deep at the point guard spot on this roster (Kemba Walker and White are the only true point guards, a couple of players such as Marcus Smart can play a few minutes there but aren’t really suited to the position).

Team USA has one more exhibition game against Canada, then opens World Cup play on Sept. 1 in China against the Czech Republic.

Grizzlies officially waive Dwight Howard, first step on his path to Lakers

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Lakers fans are uncomfortable with it, but the Lakers did a good job hedging their bet with a non-guaranteed contract: Dwight Howard is coming to the Lakers.

That process started on Saturday with the Grizzlies officially waiving Howard.

In theory, any team could claim Howard off waivers. In practice, no team is picking up his full $5.6 million salary.

Howard gave back $2.6 million in his buyout with the Grizzlies, which is exactly how much his veteran minimum contract with the Lakers will pay him.

Howard and JaVale McGee will have to tag team to play all the minutes at the five the Lakers need. Anthony Davis is their best center (and it’s not close, he’s arguably the best center in the NBA) but he wants to play the four most of the game, so for 30 minutes a night the Lakers need another big body at the five.

Howard has the potential to fill that role. For three seasons, from 2015-16 to 2017-18, Howard averaged 13+ points and 12 rebounds a night, was a big body on defense, and played at least 71 games in averaging 30 minutes a night. Exactly the kind of player the Lakers could use. The problem was Howard was never happy those years just playing that defense/set-a-pick-and-roll/rebound role. He wanted more touches and particularly in the post, which led to disruptions as he pushed for a larger role. It’s why he bounced around. Then last season he played just nine games due to more back and hamstring issues.

Howard is saying all the right things about accepting that role, and he convinced the Lakers to a degree, but that non-guaranteed contract shows the Lakers go into this eyes wide open. If Howard is up to his old antics, the Lakers can cut bait and move on.

It’s among the many things to watch in what should be an entertaining Lakers’ training camp this year.

On Mamba Day (8/24), former Lakers’ trainer Gary Vitti talks about what made Kobe great

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Kobe Bryant’s work ethic is legend.

It takes talent to become an MVP, 15-time All-NBA, 18-time All-Star, and lock future Hall of Famer. However, it was how Kobe got the most out of his talent that separated him from his peers. Long-time Lakers trainer Gary Vitti retired a couple of years ago and will soon publish an autobiography, “32 Years of Titles and Tears from the Best Seat in the House: What I Learned about Happiness, Greatness, Leadership and the Evolution of Sports Science.”

Vitti joined Hall of Fame photographer Andrew D. Bernstein this week on an episode of Legends of Sport to discuss his upcoming book, and he talked about Kobe (hat tip to CNBC).

“He was talented, but what if I told you he wasn’t the most talented guy out there? I’m telling you, and I’ve had them all, there’s nothing really special about Kobe. I mean he’s a big guy, but he’s not that big. He was quick, but he’s not that quick. He’s fast, he wasn’t that fast. He was powerful, but he wasn’t that powerful. I mean, there were other players that had more talent than he did, so what was there about him that more talented players had zero rings and he ended up with five?…

“He was tough in the sense that he took ‘can’t’ and ‘won’t’ out of his lexicon and he just believed that he could do it. Kobe taught me that talent is the most overrated thing in life; it’s what you do with your talent.”

Nobody in NBA history did as much with the talent they had as Kobe.

On Mamba Day, enjoy his ultimate mixtape highlights above and remember what it took for Kobe to get there.

 

Shai Gilgeous-Alexander: ‘I am not Russell Westbrook. I’m just going to try to be myself.’

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Thunder fans are going to love Shai Gilgeous-Alexander.

The Clippers did not want to give him up in the Paul George trade but had no real choice — Gilgeous-Alexander was a prize get for OKC. As a rookie last season he started 73 games, averaging 10.8 points and 3.3 assists per game for a 48-win playoff team. Playing the most difficult position to learn in the NBA. Gilgeous-Alexander grew as the season wore on and has a promising future.

But he is taking over for Russell Westbrook as the point guard for the Thunder, so the comparisons are inevitable. Even though they have radically different games. Gilgeous-Alexander handled the question well when asked, as reported by Erik Horne at The Oklahoman.

Gilgeous-Alexander smiled and said he could compete with Westbrook’s fashion sense. He also deflected any notion of pressure to live up to the legacy of the 2016-17 Most Valuable Player. “He set the bar pretty high,” Gilgeous-Alexander said…

“I am not Russell Westbrook,” Gilgeous-Alexander said with no malice. “I do not have the same name, same body type, stuff like that. So, I’m just going to try to be myself and be the best me and everything else will take care of itself.

“I’m just a basketball player. Regardless of the situation, I’m going to continue to work hard and play my game. I know that eventually it will come out. I don’t worry about starting. I’m not worried about accolades or things like that. I just work hard, keep my head down and (stay) true to who I am.”

That attitude is part of why Thunder fans will love him. Gilgeous-Alexander is confident but not cocky, and he knows his game.

That game is more traditional point guard, more game manager, than the dynamic and explosive Westbrook. Gilgeous-Alexander learned for a season under a smart, player-friendly coach in Doc Rivers, who built his point guard’s confidence up as the season wore on. Rivers showed the rookie how to be a professional, how to prepare, and most of all trusted Gilgeous-Alexander — and that trust included being matched up on Stephen Curry in a playoff series. Through it all, Gilgeous-Alexander showed real promise.

Whatever is next in Oklahoma City — and there is a lot of rebuilding to do with that roster, a lot of picks to be made still — Gilgeous-Alexander can help lead it. He will be at the heart of what is next for the Thunder.

Just don’t expect him to be Westbrook. There is only one of those.