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. 

James Harden’s 37 helps Rockets over Celtics 107-106

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HOUSTON (AP) — Houston’s coaching staff emphasized to the players that Boston led the league in fourth-quarter scoring.

So when they Rockets found themselves down by six entering the final frame they knew they’d have step things up to escape with a win.

Harden made sure they did that, scoring 13 of his 37 points in the fourth before Al Horford missed a shot just before the buzzer to allow the Rockets to hold on for a 107-106 victory Monday night.

“The fourth quarter we just picked up … we just wanted to lock in and get stops and offensively be aggressive,” Harden said.

The game was tied before Harden scored five straight points to make it 107-102 with less than a minute remaining. Avery Bradley made a jump shot and Harden received a flagrant 1 foul for elbowing Marcus Smart in the face. Smart made both free throws before Isaiah Thomas missed a layup.

But Houston knocked the ball out of bounds with 5.2 seconds left, giving Boston one last chance. Horford drove into the lane, but his shot rolled off the rim and Harden grabbed it to secure the victory.

“I felt good when I shot it, but it just didn’t go down,” Horford said.

Horford had 21 points and Thomas added 20 for the Celtics, who had won two straight.

It was the ninth 30-point game this season for Harden, who also had eight assists and seven rebounds.

An 8-2 run by Houston, powered by a pair of 3-pointers by Eric Gordon, cut Boston’s lead to one with about 8 1/2 minutes left. Smart made a 3-pointer for the first of seven straight points for the Celtics that made it 96-88. Smart also had a big defensive play in that stretch when he blocked a one-handed dunk attempt by Montrezl Harrell.

Houston scored eight straight points, topped off with a dunk from Harrell, to take a 102-100 lead with about 3 1/2 minutes left.

Harden raved about Harrell’s work.

“You see how he’s flying around everywhere,” Harden said. “He does a lot of different things, some things that don’t show up on the stat sheet that helped contribute to this win.”

The Celtics trailed by 12 early in the third quarter before using a 15-2 spurt to take a 68-67 lead with about 7 minutes left in the quarter. Boston made three 3-pointers in that span, capped by one from Horford. Houston missed five shots, including four 3s, and had two turnovers to help the Celtics close the gap.

“We guarded at a different level and our first unit played pretty well in the third,” Celtics coach Brad Stevens said. “In one stretch in the fourth we turned the ball over and that was hurtful.”

The Rockets were up by three points with 2 minutes left in the first half before Smart fouled Harden on a 3-point attempt and he made all three free throws. Houston had extended the lead to seven when Smart again fouled Harden on a 3-point try and his three free throws made it 58-48 at halftime.

TIP-INS

Celtics: James Young missed the game with an illness. … Thomas received a technical for arguing a call at the end of the first half. … Bradley finished with 16 points and 10 rebounds. … Smart had 13 points.

Rockets: Made 12 3-pointers to extend their NBA record of consecutive games with at least 10 3-pointers to 20. … Trevor Ariza started despite dealing with back spasms and had 15 points and eight rebounds. … Gordon finished with 19 points and made four 3-pointers to give him six straight games with at least four 3s.

PERFECT

Harden tied a franchise record for most free throws without a miss by making all 18 of his attempts on Monday night. Kevin Martin also went 18 for 18 on March 20, 2011 against Utah. He lamented committing the offensive foul on Smart late instead of drawing the foul and getting a chance to go to the line and set the record.

“Of course I wanted two free throws at the end of the game instead of a flagrant, but we won,” he said. “That’s all that matters.”

LATE PUSH

The Rockets have developed a knack for scoring late. After managing just 13 points in the fourth quarter of a 105-103 loss to Oklahoma City on Nov. 16 the Rockets have picked things up, averaging 27.9 fourth-quarter points in the last 10 games.

THEY SAID IT

Stevens on Harden: “Harden is a really good player. I don’t know what else to say. We could go through and dissect every play, but overall he is just a really good player.”

 

Insane: Klay Thompson drops 60 on Indiana in three quarters (VIDEO)

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Oh yea, don’t forget the Golden State Warriors have Klay Thompson, too.

It’s not that the Indiana Pacers forgot, they just couldn’t do anything about it. Thompson hit 21-of-33 shots, 8-of-14 from three, on his way to 60 points in three quarters as the Warriors ran the Pacers out of Oracle Arena 142-106. Thompson was hitting from anywhere and everywhere.

Klay shotchart

The rest of the Warriors loved it.

Russell Westbrook’s sixth straight triple-double leads Thunder past Hawks 102-99

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ATLANTA (AP) — Russell Westbrook extended his streak of triple-doubles to six games, leading the Oklahoma City Thunder to a 102-99 victory over the skidding Atlanta Hawks on Monday night.

Westbrook scored 32 points, grabbed 13 rebounds and doled out 12 assists, giving him the NBA’s longest streak of triple-doubles since Michael Jordan had seven in a row in 1989.

Westbrook’s run has sparked a six-game winning streak by the Thunder. He’s now reached double figures in all three categories in half of the Thunder’s 22 games.

By contrast, Jordan had 15 triple-doubles for the entire 1988-89 season.

Westbrook kept his streak alive with plenty of time to spare. Despite a poor start shooting, he already had 15 points and 11 rebounds when he picked up his 10th assist with 6:20 left in the third quarter.

Scooping up a loose ball after a turnover by the Hawks, Westbrook led a 2-on-1 that ended with a pass to Victor Oladipo for a layup that gave the Thunder a 69-59 lead.

Westbrook, who missed eight of his first nine shots, suddenly found his touch in the third quarter. He made five of his next seven shots, three of them beyond the arc, and finished with 16 points in the period as the Thunder stretched a one-point halftime lead to 83-69 heading to the fourth.

Atlanta rallied down the stretch, but Westbrook closed it out for the Thunder. He finished with 27 second-half points to send the Hawks to their seventh straight loss and 10th defeat in the last 11 games.

It’s the longest losing streak for the Hawks since they dropped eight in a row in February 2014.

Coach Mike Budenholzer decided to shake things up, sending Kyle Korver to the bench and putting Thabo Sefolosha in the starting lineup. The Hawks also were bolstered by the return of Paul Millsap, who had missed three straight games with a sore hip. He led five players in double figures with 24 points.

It didn’t matter. Westbrook made sure of that.

Atlanta had a shot to send the game to overtime after Korver forced a jump ball.

The Thunder clamped down defensively off the inbounds play, and Tim Hardaway Jr.‘s desperation 3-pointer at the buzzer failed to hit the rim.

MONSTER JAM

Oladipo wasn’t afraid to take on Dwight Howard in the lane.

During the second quarter, the 6-foot-4 Thunder guard drove the baseline and slammed one over Atlanta’s 6-11 center, rocking the rim and drawing gasps from the crowd.

Oladipo savored the moment, pumping his fists, stomping his feet and posing briefly in the lane even as the Hawks took off the other way.

RECRUITING DWIGHT

Billy Donovan made a recruiting pitch to Howard while coaching at Florida.

During his pregame chat with the media, the Oklahoma City coach recounted a visit to Howard and his father at Southwest Atlanta Christian Academy.

Donovan quickly gave up any hope of getting Howard to attend college.

“All I had to do was watch one AAU game and then I stopped recruiting him immediately,” he quipped.

Howard, of course, went straight from high school to the NBA in the days before the rules required at least one year of college. He was the first overall pick of the Orlando Magic in 2004.

 

Follow Paul Newberry on Twitter at http://www.twitter.com/pnewberry1963 . His work can be found at http://bigstory.ap.org/content/paul-newberry .

Al-Farouq Aminu active for Trail Blazers

PORTLAND, OR - APRIL 25: Al-Farouq Aminu #8 of the Portland Trail Blazers celebrates with a teammate after hitting a three point shot in the first quarter of Game Four of the Western Conference Quarterfinals against the Los Angeles Clippers during the 2016 NBA Playoffs at the Moda Center on April 25, 2016 in Portland, Oregon. NOTE TO USER: User expressly acknowledges and agrees that by downloading and/or using this photograph, user is consenting to the terms and conditions of the Getty Images License Agreement. (Photo by Steve Dykes/Getty Images)
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CHICAGO (AP) — Portland Trail Blazers forward Al-Farouq Aminu is active for their game against the Chicago Bulls after being sidelined by a left calf injury.

Coach Terry Stotts says Aminu will be restricted to around 20 minutes Monday night “depending on how it goes.”

Aminu started the first eight games of the season before he got hurt Nov. 8 against Phoenix. He is averaging 6.4 points and 6.6 rebounds.