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. 

‘One Piece’ fans are trying to get Steven Adams into the All-Star Game

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There’s been a lot of clever NBA All-Star marketing over the years. Portland Trail Blazers guard CJ McCollum did a “Napoleon Dynamite”-themed video for his buddy Damian Lillard this season. The Toronto Raptors made a faux-vintage action figure ad for Kawhi Leonard.

Now it appears that anime website Crunchyroll is trying to get “One Piece” fans to vote for Oklahoma City Thunder big man Steven Adams.

Adams is a fan of anime, and has professed his admiration for the show “One Piece” before. Adams made mention about how he was watching the show instead of Kevin Durant‘s debut with the Golden State Warriors a while back. In turn, Crunchyroll — a streaming site — made a video trying to get people to vote for Adams in the NBA fan vote.

Via Twitter:

That’s pretty good, but will it be enough? We know the fan vote gets wild, especially with favorites who are sort of undeserving (Derrick Rose and Luka Doncic come to mind). Could a big push from the anime crowd help Adams, who is an excellent player but who has never been an All-Star, notch his first bid?

Luka Doncic got ejected for kicking a ball into the stands (VIDEO)

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Luka Doncic is a young man, still just 19 years old. The Dallas Mavericks forward has been a pro for some time now, but he still has things to learn.

For example, in the NBA you can’t kick a basketball and expect not to get a technical foul just because you’re a star.

Doncic was standing near the ball during the fourth quarter when he decided to get it a little boot, sending it into the stands. That earned Doncic his second technical of the night, earning him an ejection.

Via Twitter:

You can’t kick a basketball, my son.

Spurs expect DeMar DeRozan back Sunday vs. Clippers

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The San Antonio Spurs hope to be at or near full strength when they host the Los Angeles Clippers on Sunday. The Clippers can’t even hope to be that fortunate on the injury front.

The Spurs head home after sweeping a two-game road trip, in Dallas and Minneapolis, with the latest win a 116-113 nail-biter against the Minnesota Timberwolves on Friday.

Marco Belinelli canned a pair of crucial free throws with 4.2 seconds the play to cement the win while LaMarcus Aldridge poured in 25 points in a contest that was close throughout, with 27 lead changes and 17 ties through the middle of the fourth quarter.

Rudy Gay scored 22 points for the Spurs, while Belinelli racked up 19 points, Derrick White added 15, and Davis Bertans and Bryn Forbes poured in 11 and 10 points, respectively.

“We got through some stuff, and it’s always good to win on the road,” Spurs coach Gregg Popovich said afterward. “It’s always difficult to do, but when you do it feels pretty good.”

The Spurs have now won 16 of their past 18 games against Minnesota. The victory was accomplished even though San Antonio played without leading scorer DeMar DeRozan, who aggravated a left ankle injury in pregame warmups and was ruled out just prior to tipoff.

Popovich said DeRozan likely will return against the Clippers.

“He has a lot of bumps and bruises,” Popovich told the San Antonio Express-News or DeRozan. “He came in stiff on Friday. His thigh has been hurting and his ankle. He has been playing a lot of minutes, more than most people, and it seemed better to let his body recover.”

Popovich garnered his 520th career win on the road, tying Pat Riley for the most in NBA history.

The Clippers travel to south Texas on the heels of a 112-94 home loss to Golden State on Friday. It was Los Angeles’ season-worst fifth straight defeat.

Tobias Harris led the Clippers with 28 points while rookie guard Shai Gilgeous-Alexander matched his career high with 24. No other Los Angeles player scored more than seven points.

“We didn’t have a lot of scoring out on the floor tonight,” Los Angeles coach Doc Rivers said afterward.

The Clippers played without injured sixth man Lou Williams, who is battling a sore right hamstring. Rivers also said that Williams, who suffered his injury Wednesday against the Utah Jazz, is likely to miss the next couple of games.

“It was tough on me because in the third quarter, second half, we needed that extra scoring threat,” Harris told the Los Angeles Times. “We need other guys to pick up the load and just be ready to play. That’s our mentality and we’ll be ready for it.”

To make matters worse, Los Angeles forward Danilo Gallinari was forced from the game after eight minutes with lower back spasms and didn’t return.

“He got hit in the game early and you could see his movement was wrong,” Rivers said of the decision to pull Gallinari. “I asked him early, and he said he got hit in the back, said he wanted to go a little bit more. Then I saw him moving and I was like, ‘Time to go home.'”

The Clippers will monitor Gallinari’s back as they head out on a four-game road trip that begins in San Antonio.

The Spurs have taken two of the three games with Los Angeles this season and own a 72-13 edge at home in the all-time series.

–Field Level Media

Watch James Harden score MVP-like 48, lift Rockets past Lakers in OT

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HOUSTON (AP) — James Harden scored 48 points, Eric Gordon added 30 and the Houston Rockets overcame a 21-point deficit to beat the Los Angeles Lakers 138-134 in overtime Saturday night.

The Rockets trailed for most of the night and were down by 18 in the second-half. Gordon sent it to overtime with a 3-pointer, and made four free throws in the last seconds of the extra period.

Coming off 57- and 58-point games, Harden had his 19th straight game with at least 30 and he’s had 40 in 10 of the last 13. He was 14 of 30 from the field, going 8 of 19 3-pointers, and hit 12 of 15 free throws.

Brandon Ingram missed a 3 for Los Angeles before Harden hit 1 of 2 free throws to make it 132-130 with less than a minute left. Ingram tied it with a basket, and Harden again made 1 of 2 free throws to make it 133-132.

Los Angeles missed a 3 before Gordon also made just 1 of 2 free throws to leave Houston up by two with 12.6 seconds left. Kyle Kuzma lost the ball and it went out of bounds to give Houston the ball back. Gordon added four free throws after that to secure the victory.

It was the second straight overtime game for both teams after Houston lost to Brooklyn on Wednesday night and Los Angeles beat Oklahoma City on Thursday night.

Kuzma had 32 points for Los Angeles and Ingram added 21 in a game where coach Luke Walton was ejected in the third quarter.

Already without LeBron James and Rajon Rondo, the Lakers have another injury concern after Lonzo Ball sprained his left ankle in the third quarter. The team said he was taken to a hospital for X-rays because the machine at the arena was broken.

Four straight points by the Lakers stretched the lead to nine in the fourth quarter, but Harden and Gordon made consecutive 3-pointers cut it to 112-109 with about two minutes remaining.

Los Angeles made four free throws to make it 116-109 about a minute later, but Harden made two 3-pointers around a basket by Ivica Zubac to get Houston within three with about 30 seconds left.

Lance Stephenson missed a 3-pointer and Harden made two free throws to cut the lead to 118-117 with 5.7 seconds left.

Zubac made two more free throws before Gordon’s off-balance 3-pointer with 2 seconds left sent it to OT.

The Lakers built a huge lead early and were up 64-46 at halftime, with Kuzma scoring 24 points.

They were ahead by 17 with about eight minutes left in the third quarter after scoring five straight points capped by a basket from Kuzma before Houston scored the next 15 points to cut it to 74-72 three minutes later. James Ennis had five points in that stretch and P.J. Tucker capped it with a 3-pointer.

Ball was injured just before Houston’s run began. He remained on the court for a couple of minutes talking with trainer’s before he was helped to his feet where he hopped on his right foot for a few steps before being carried off the court and to the locker room by Stephenson and Michael Beasley.

Walton was ejected a couple of minutes after that when he got two technical fouls after yelling at officials during a timeout.