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. 

Andrew Bogut comes up big for Warriors, who so often shun him to go small

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The Warriors’ Nuclear Lineup propelled them to the 2015 NBA championship. It has drawn praise from the President of the United States. It has been credited with revolutionizing basketball.

And it has marginalized Andrew Bogut.

Golden State has been at its best the last two years when benching Bogut for Andre Iguodala and shifting Draymond Green to center. That small-ball unit has defended well, pushed the pace and found quality shots.

But with the death lineup looking more vulnerable than ever – and, really, vulnerable at all for the first time – the Warriors turned to the starter who had sat and cheered his teammates in the biggest moments.

Bogut scored 15 points (his career playoff high) and grabbed 14 rebounds (his 2016 postseason high) in the Warriors’ Game 5 win over the the Thunder.

The biggest number: Bogut’s 30 minutes.

He played just 17, 16, 12 and 11 minutes in the series’ first four games. Foul trouble contributed, but so did Golden State’s sloppiness – turnovers and quick shots – that turned games into track meets. At 7 feet and age 31, Bogut isn’t built to keep up. But the Warriors slowed the game just enough to let Bogut shine.

Protecting the paint has two major components:

1. Preventing shots at the rim. Even the worst finishing teams score at point-blank range more efficiently than the best mid-range teams do between the paint and 3-point arc.

2. Forcing misses at the rim when the opponent gets off a shot. Obviously.

Golden State improved tremendously in both areas tonight.

The Warriors allowed a series-low 18 attempts in the restricted area:

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And they held Oklahoma City to a series-low 44% shooting in the restricted area:

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Add it up, and that means the Thunder made just eight shots in the restricted area – a third as many as Game 3 and half as many as any other game:

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Bogut was central to the interior defense. Oklahoma City shot just 3-for-10 (30%) in the restricted area with him on the floor and 5-for-8 (63%) with him off.

“Bogues is our best defender,” Warriors coach Steve Kerr said, providing news to the voters who picked Golden State forward Draymond Green second in Defensive Player of the Year voting.

Green defended well tonight. But Bogut – who had two blocks and two steals – really drove the turnaround.

“It’s probably the key if you want to look for one thing – Bogues’ play leading to better defense,” Kerr said.

Add his quality finishing (7-for-9 from the field) and plus passing from the post (which generated two assists), and this was a real gem from Bogut – at a time the Warriors needed it most.

But can Bogut help them in Game 6 Saturday in Oklahoma City? He hasn’t played 30 minutes twice in three days in more than a year.

“I believe in Bogues,” Kerr said. “I think he can play that way in Game 6.”

Golden State will need him – or another way to defend the paint. Given the results of this series so far, including Green uncharacteristically struggling to protect the rim as the small-ball center, I’d turn to Bogut again.

Stephen Curry attacks rim, makes defensive plays, lifts Warriors to 120-111 win

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Stephen Curry wasn’t hitting threes like the video-game version of himself (the one we have come to expect), so he attacked the rim and made plays in the paint. The result was 31 points on 20 shots — and he set the tone for the Warriors all night.

Not just on offense, Curry had a key steal plus blocked a Kevin Durant shot late — highlighting an improved Warriors defense.

“I thought he looked like 91 percent,” Warriors coach Steve Kerr joked about Curry after the game (referencing the report Curry is just 70 percent healthy).

Curry played better than he had since Game 2 — so did Draymond Green, who had some offensive struggles but played the defense we know. The Warriors also got 27 points from Klay Thompson, and 15 points plus a lot great play in the paint from Andrew Bogut allowing the Warriors to stay with bigger lineups. Also, with Golden State attacking the rim, they got to the free throw line 34 times.

The result of all of it was a 120-111 Golden State win at home in Game 5, making the series 3-2.

Now the biggest test of the season comes for the Warriors — they will need to play better than this Saturday on the road in Oklahoma City to force a Game 7.

“We played with great energy, we played with great desperation, that’s the way you have to play in the playoffs,” Kerr said. “We were out of sorts the last two games, and we looked more like ourselves.”

The best way to describe Curry’s night was “good enough.” Credit to him attacking when his threes were not falling, look at his shot chart on the night.

Curry Game 5 shot chart

The Warriors also took the Thunder out of what had been successful for them the past couple games — OKC had just 15 fast break points (compared to 28 for the Warriors), the Warriors were +18 on points in the paint, and the Warriors outrebounded the Thunder on the night. The Warriors didn’t overthink thier defense on the Thunder in this one, they just did a better job of executing switches and, thanks to Bogut, taking away easy buckets inside.

Russell Westbrook and OKC struggled out of the gate — as a team, they shot 8-of-28 in the first quarter and at one point Westbrook missed 10 shots in a row. The Warriors were not hot with their typical shots — 2-of-10 from three — but they were getting to the rim and finishing better inside, which got them a lead in a game where Oracle Arena is rocking.

Steve Kerr did not dramatically change what had worked so well for Golden State all season, counting on his team to just be better — and it was, they outscored the Thunder small-ball lineup 20-15 in the first half (after being destroyed by it in the previous two games). The Thunder hung around in the second thanks to mid-range jumpers (5-of-7 in the second, plus 3-of-5 from three). But the Thunder did not get the same lift from their stars, Kevin Durant had 15 first half points on 15 shots, Westbrook had 13 on 14 shots (but still had six assists). Golden State led 58-50 at the half.

The Thunder opened the second half on a 9-2 run and things yo-yoed between tied and a small Warrior lead for much of the second half, until the Golden State’s bench pushed the lead into double digits again late in the third and early in the fourth. That lead held until the six-minute mark in the fourth quarter, when the Thunder went on an 8-0 run fueled by some sloppy Warriors turnovers.

But the Warriors showed more poise than they have in the past few games, holding on for the win, making plays at the end when they needed to.

Now, can they do that and better on the road?

Draymond Green banks in shot from logo after whistle (video)

OAKLAND, CA - MAY 26:  Draymond Green #23 of the Golden State Warriors warms up prior to Game Five of the Western Conference Finals against the Oklahoma City Thunder during the 2016 NBA Playoffs at ORACLE Arena on May 26, 2016 in Oakland, California.  (Photo by Thearon W. Henderson/Getty Images)
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Draymond Green missed both his 3-pointers prior, but he made this.

Unfortunately for the Warriors, it didn’t count because it came after a whistle (that few heard over the loud Golden State fans).

Stephen Curry sunk a 3-pointer later in the possession. That one counted.

Report: Khloe Kardashian files for divorce from Lamar Odom

Khloe Kardashian Odom, Lamar Odom
AP Photo/Evan Agostini
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1. Khloe Kardashian filed for divorce from Lamar Odom.

2. With Odom facing health problems after a drug overdose, they rescinded the filing.

3. Odom reportedly continued drinking, frustrating Kardashian.

Associated Press:

Court records in Los Angeles show Kardashian filed for divorce Thursday, citing irreconcilable differences.