The Advanced Stats Guide to the 2015 NBA MVP Race

This incredible NBA season brought with it one of the most tightly contested MVP races in recent memory. There are six incredibly qualified candidates who can each stake a worthy claim to the award: Stephen Curry, Anthony Davis, James Harden, LeBron James, Chris Paul and Russell Westbrook. 

Each of these candidates has a compelling narrative case in his favor: 

• Curry was the best player on the league's best team.
• Davis was the NBA's breakout superstar and arguably had the best overall season.
• Harden carried a comparatively weak team to the No. 2 seed in one of the toughest conferences in recent memory.
• James is still the best player on Earth and completely revitalized the city of Cleveland and the Cavaliers franchise.
• Paul had arguably the best season of his career on both ends of the floor, helping carry the Los Angeles Clippers to the West's third seed, even with a horribly thin bench and an extended absence from Blake Griffin.
• Westbrook put up numbers that are unheard of in the history of the league and dragged an undermanned, injury-ravaged team to the brink of the playoffs. 

But the narrative's not the only thing that matters; What about each player's statistical case? Research conducted in 2013 by our friend Ian Levy at Hardwood Paroxysm showed that approximately 51 percent of variance in MVP voting could be attributed to statistics. 

With that in mind, let's take a holistic look at each player's case through the lens of advanced stats. We'll work through a bunch of all-in-one metrics before taking a look to the past to see which of those numbers may be indicators that the vote will swing one way or another. 

PER: Player Efficiency Rating; a rating of a player's per-minute productivity

It is generally considered a decent measure of a player's offensive capabilities, but it does not capture much in the way of defense. Davis is the leader here, having registered the 11th-highest PER of all time, while becoming the first player not named Michael Jordan, Wilt Chamberlain or LeBron James to top 30 in a single season.

WS: Win Shares; an estimate of the number of wins contributed by a player

Harden leads the way for this measure, though much of that is thanks to his extraordinary minute load. If you break Win Shares down to WS/48, a measure of Win Shares Per 48 Minutes, Curry moves into a commanding lead, and Harden drops down to third.

WP: Wins Produced; a model for estimating individual player contribution to winning, as determined by Dave Berri's Wages of Wins team

WP has different weights than both PER and WS, and here Paul comes out on top largely thanks to his efficient shooting and avoidance of turnovers. However, when adjusting for minutes played by breaking it down to WP/48, or Wins Produced Per 48 Minutes, Curry again slides into the catbird seat.

BPM: Box Plus/Minus; a box score estimate of the points per 100 possessions a player contributed above a league-average player, translated to an average team

Westbrook, on the strength of his remarkable counting stats, comes out on top in BPM. His 11.0 score here has only been topped eight times in NBA history, all by James, Jordan or Paul.

VORP: Value Over Replacement Player; a box-score estimate of the points per 100 team possessions a player contributed above a replacement-level player, translated to an average team and prorated to an 82-game season

Curry, Paul and Westbrook are far ahead of the rest of the pack.

WAR: Wins Above Replacement; the estimated number of team wins attributable to each player, based on RPM

There's no playing-time adjustment baked into WAR, and once again Harden tops this list, thanks to his incredible production across a massive number of minutes played.

RPM: Real Plus-Minus; a player's estimated on-court impact on team performance, measured in net point differential per 100 offensive and defensive possessions

RPM takes into account teammates, opponents and additional factors and is essentially WAR adjusted for playing time. Curry comes out far ahead of the field.

DRE/100: Daily RPM Per 100 Possessions; an estimate of net points contributed per 100 possessions, using a regression of linear weights against RAPM

When adjusting RAPM for possessions rather than minutes, Davis edges ahead of Curry.

PIE: NBA.com's Player Impact Estimate; measures a player's overall statistical contribution against the total statistics in games they play in

This essentially boils down to the percentage of box-score stats a player totals while he is on the floor, and Davis surprisingly clips Westbrook for the top spot.

Net: Net Efficiency; the number of points per 100 possessions by which a player's team performed better or worse with him on the floor compared to when he left it

For example, the Clippers outscored opponents by 12.2 points per 100 possessions with Paul on the floor and were outscored by 7.6 points per possessions when he was out of the game. Therefore, his Net Efficiency is a league-high 19.8 (12.2 minus -7.6).

Looking to the past

We don't have historical data available beyond the 2013-14 season for WAR or RPM or beyond this season for DRE/100, but in each of the other metrics, we can take a look at the last five MVP races to see where the winners and other contenders ranked in each category. 

2009-10

LeBron James (1), Kevin Durant (2), Kobe Bryant (3), Dwight Howard (4), Dwyane Wade (5)

James led all candidates—and the entire league—in all categories.

2010-11

Derrick Rose (1), Dwight Howard (2), LeBron James (3), Kobe Bryant (4), Kevin Durant (5)

James led in PER, Win Shares, WS/48, BPM, VORP and PIE, while checking in second among this group in Wins Produced and WP/48, but it was Howard who led in both of those categories.

This was a season where there was such a strong narrative momentum against James due to his decision to leave Cleveland for the Miami Heat that it pushed the award away from him and to Rose, whose Bulls finished with the East's best record behind his ascent to stardom.

Rose, though, finished fifth among this group in PER, third in Win Shares, WS/48, Wins Produced, WP/48 and PIE and second in BPM and VORP. He did not have a strong statistical case for the award.

2011-12 

LeBron James (1), Kevin Durant (2), Chris Paul (3), Kobe Bryant (4), Tony Parker (5)

LeBron again led the group—and the league—in all categories, and most of them weren't that close.

2012-13

LeBron James (1), Kevin Durant (2), Carmelo Anthony (3), Chris Paul (4), Kobe Bryant (5)

James led in PER, Win Shares, WS/48, BPM, VORP, Wins Produced and PIE, but he finished second (to Paul) in WP/48.

2013-14

Kevin Durant (1), LeBron James (2), Blake Griffin (3), Joakim Noah (4), James Harden (5)

Durant finished first in PER, Win Shares, WS/48, VORP, Wins Produced and PIE and second (to James) in both WP/48 and BPM.

How the Winners Fared and How It Applies to This Year's Race

The PER leader won the MVP in four of the five seasons, as did the Win Shares, WS/48, VORP, Wins Produced and PIE leader. Meanwhile, the BPM leader won in three of five years, while the WP/48 leader won only two of five.

Here's the thing: Davis led in PER and PIE, Harden led in Win Shares, Paul led in Wins Produced, Westbrook led in BPM and Curry led in WS/48, WP/48 and VORP. So the indicators are all over the place, with nobody claiming an overwhelming statistical edge like James and Durant did in previous years.

After ranking each player from one through six (one for first place, six for sixth place, so a lower score is better) based on their finish in each of these 12 all-in-one metrics (including the ones for which there isn't much in the way of historical data), though, Curry comes away with by far the best overall score. He led the group in WS/48, WP/48, VORP and RPM and didn't finish lower than fourth in any category. The full results:

Player	Score
Stephen Curry	24
James Harden	37
Chris Paul	38
Anthony Davis	40
Russell Westbrook	53
LeBron James	60

Since nobody ran away with the statistical MVP case by dominating every category, Curry's high marks across the board would seem to tip the result in his favor.