Our Daily Dread: The pluses and minus of the NBA’s use of the +/- stat

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It’s been in the NBA game summaries now on nearly all Internet sports sites for some time now — on each player’s line of minutes played, FTA-M, rebounds, assists, etc., is a category for plus/minus, just like in the NHL. It measures how effective the team is performing when that player is on the court. A high plus number doesn’t necessarily mean he’s scoring a lot of points. It’s just that the team is playing better than the other team — maybe because of his passing ability, his defense, his chemistry with those on the court. The larger the minus number, the bigger the liability. In theory.

Sunday’s NBA All-Star Game boxscore (linked here) may be a bit of a skewed look at how this stat worked, but Kobe Bryant, for example, had a +24 during the game when he scored 27 points in 29 minutes. Shaquille O’Neal, off the bench, and starting guard Chris Paul had a +21. Maybe the three of them could have shared the MVP instead just the first two.

Starting West center Yao Ming had a -2 in his 12 minutes — the only West player with a minus number in the 146-119 victory, which seems nearly impossible to achieve.

The interesting part is to see who, on the other team, did the West exploit the most. Not starting guard Dwayne Wade had a +8 in 27 minutes, pretty incredible for a game that ended with his team losing 27 points. Allen Iverson had a +1 in 16 minutes, and he only scored 2 points. Kevin Garnett had a 0 in 19 minutes, meaning the 12 points he scored were offset by 12 by the West.

The other two East starters — LeBron James (-14) and Dwight Howard (-16) were a combined -30 with a combined 55 minutes. That’s kind of strange considering Howard had three blocks and nine rebounds.

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The biggest holes in the East defense — reserve point guard Devin Harris, a -31 in just 17 minutes. And that includes his six points, plus an awkward landing on Maria Shriver when he went after a loose ball (pictured here). Compare that to another reserve East point guard, Mo Williams, who had a +1, also in 17 minutes. See the difference?

Shooting guard Joe Johnson had a -28 in 22 minutes, which explains 0 points, 5 turnovers, 0 steals, 0 assists and 0 rebounds. You’d have thought that East power forward Rashard Lewis would have been worse than a -11, since O’Neal exploited his size advantage to pick and roll on him for a lot of the second and fourth quarters. But in his 21 minutes, Lewis also had 8 points. Paul Pierce’s -19 was also pretty glaring.

Yes, it was only an exhibition. A closer test to how a player performs statistically for his team on a regular basis can be used with an ESPN-created formula (linked here) that goes — PTS + REB + 1.4*AST + STL + 1.4*BLK -.7*TO + FGM + .5*TGM -.8*(FGA-FGM) + .25*FTM – .8*(FTA-FTM). It equals to James leading the league (49.8) by a larger margin (3.5) over second place Wade than they are in simply the points category (where James currently leads by 0.2 a game). The NBA.com page also has a ranking of player efficiency (linked here) that also shows James leading.

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The NBA must think the plus-minus stat is good enough because it has a title sponsor for it on its webpage (linked here). It breaks it down into which five players on any of the 30 teams has the best plus/minus on a nightly basis. The league leader in plus/minus one night was … we’d give 100 guesses before you might stumble on Golden State’s second-year man Kelenna Azubuike, who had a +15 the other night.

If you’re looking at a group of players, the Lakers with Bryant, Luke Walton, Pau Gasol, Lamar Odom and Derek Fisher does better than if Andrew Bynum is in for Odom (linked here). But a lineup of Bryant-Fisher-Gasol-Odom and Trevor Ariza is still in the top 50 of the league.

This loops around to the fact that maybe the East could have had a better shot of winning that game Sunday if it could have borrowed Shane Battier to guard Bryant on the West.

The cover story in Sunday’s New York Times magazine (linked here), with Houston’s Battier and Rockets GM Daryl Morey as the focus, was done by Michael Lewis, famed for his 2003 book “Moneyball: The Art of Winning an Unfair Game” on Oakland Athletics GM Billy Beane’s approach to squeezing the most from what little payroll he has to work with. Lewis calls Battier a “true all-star” based on the way 33-year-old Morey used his MIT degree to figure out how the Rockets could operate with the salary cap despite the fact that large chunks of it were already allocated to players such as Ming and Tracy McGrady.

The plus-minus stat is one that Morey really pays attention to.

“In its crude form, plus-minus is hardly perfect,” writes Lewis. “A player who finds himself on the same team with the world’s four best basketball players, and who plays only when they do, will hae a plus-minus that looks pretty good, even if it says little about his play. Morey says he and his staff can adjust for these potential distortions — though he is coy about how they do it — and render plus-minus a useful measur eof a player’s effect on a basketball game. A good player might be a plus 3 — that is, his team averages 3 points more per game than its opponents when he’s on the floor.”

In his best season, Phoenix Suns guard Steve Nash was a +14.5.

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For the sake of this story, it’s pointed out that Battier, who is often at a +10, has a +6 for his career.

“Plus 6 is enormous,” says Morey in the story. “It’s the difference between 41 wins and 60 wins.” It’s in the category of a Vince Carter, Carmelo Anthony … and McGrady. Yes, Battier is in that classification if you’re looking for someone with team value.

Even more intriguing from the story’s aspect is looking specificially at how Battier guards Bryant when the Rockets play the Lakers.

“When Battier guards Bryant, the Lakers’ offense is worse than if the NBA’s best player took the night off,” writes Lewis. There’s a quote from Morey: “The Lakers’ offense should obviously be better with Kobe in. But if Shane is on him, it isn’t.”

When the Lakers won at Houston 105-100 on Jan. 13, Bryant had a -1 rating, despite scoring 33 points in 42 minutes. The Lakers’ biggest game-changer was Trevor Ariza, who had 14 points in 28 minutes and a game-high +12. Battier had just a -3 in 29 minutes, scoring just 3 points. Brett Barry was the only Rocket in that game to have a positive number (+2).

The Lakers have two more games against Houston — March 11 on the road and April 3 at home. Keep the dates circles to see how that Battier-Bryant matchup works out.

Give your pluses and minuses to this story with a comment here or email to thomas.hoffarth@dailynews.com

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