Sports Reference Blog

Introducing BPM 2.0

Posted by Mike Lynch on February 25, 2020

Basketball-Reference is now utilizing BPM 2.0, an improved version of Box Plus-Minus. Like the original BPM, BPM 2.0 is a statistic created by Daniel Myers which aims to estimate a player's performance relative to league average by using a player's box score information and his team's overall performance. On the site, BPM 2.0 will appear just as BPM did. On player pages it can be found in 'Advanced' section with columns dedicated to OBPM (Offensive Box Plus-Minus), DBPM, (Defensive Box-Plus Minus), BPM (Box Plus-Minus) and VORP (Value Over Replacement Player). OBPM and DBPM, when summed, equal BPM. They are all rate stats. VORP is a counting stat since its inputs are BPM and playing time. As before, these statistics are all available back to the 1973-74 season (though we're hopeful to eventually extend the measure back to 1951), when critical statistics such as blocked shots, steals and offensive/defensive rebounds were first officially tracked. For the nitty-gritty details on BPM 2.0, please see Daniel Myers's explainer.

You will also notice that BPM is now calculated as a single-game statistic in the advanced section of our box scores. In the future we hope to also compute a single-game VORP and incorporate these measures into the Player Game Finder and the advanced player game logs.

To hopefully answer some questions, here's a little fabricated Q&A. Thank you to Daniel Myers for providing the insight to answer these questions.

Why was BPM changed?

The simplest answer: Russell Westbrook. Westbrook's 2016-17 MVP season graded out at 15.6 in the original BPM. Essentially, his 10.7 RPG and 10.4 APG broke the interaction terms between those statistics. So Westbrook's great season ended up being 20% better than any other season in the database, which just didn't pass the smell test. Along similar lines, assists without rebounds and rebounds without assists were penalized in the original BPM (hurting the likes of John Stockton, Steve Nash, Hassan Whiteside and Patrick Ewing).

What players were most impacted by the changes?

Including playoffs, only one player saw his career BPM change by 3.0 or more. That'd be the aforementioned Stockton, who was 3.5 under the old system and is now 6.7. He's aided by the changes in the way the assist and rebound terms interact. Further, the old system said "no rebounds = bad defender." BPM 2.0 says "elite steals, good defensive teams = good defender."

After Stockton, the next biggest change is Earl Boykins, who went from -2.3 to 0.0. This is largely attributable to his DBPM going from -3.2 to -1.4. The spread on DBPM is much smaller in 2.0 than it was in the original BPM, so the best and worst defenders moved towards the middle. The largest moves on the defensive side of the ball are all among guards formerly in the negative. Many of them are still in the negative, but less so.

Other players who moved up or down by 2.0 or more: Geoff Huston (+2.2), Larry Smith (-2.2), Dennis Rodman (-2.2), Amir Johnson (-2.2), Avery Johnson (+2.1), and Danny Young (+2.1). A common theme for the droppers is that BPM 1.0 assumed if you got a lot of minutes but had few stats that you were probably good on defense (thus justifying your minutes). That assumption is not in 2.0. Other notable risers are Kevin Durant (+1.7) since great scoring was underrated in 1.0 and Steve Nash (+1.7) who is a similar case to Stockton. Other notable droppers are guys with relatively few statistical contributions like Charles Jones (-1.9), Andrew DeClercq (-1.9), Jason Collins (-1.8) and Nick Collison (-1.8).

What player seasons were most impacted?

While Russell Westbrook's 2017 season saw the largest drop (-4.5), it actually didn't see the biggest change. That belongs to Geoff Huston, whose 1986 season went from -6.1 to -1.0. Next up is Hassan Whiteside whose 2015 season went from -0.9 to 4.1 mostly thanks to him not being punished so severely for his comically meager assist rate. Stockton also had three seasons with gains of either 4.6 or 4.7. Besides Westbrook's 2017 season, the other drops of 3.0 or more are all among big defensive specialists impacted by the constricted range of new DBPM values (Ian Mahinmi in 2018, Lucas Nogueira in 2017, Mitchell Robinson in 2019, Dennis Rodman in 1996 and 1998, Lorenzo Williams in 1995 and 1996, Kevon Looney in 2019 and DeSagana Diop in 2006).

Who was most-impacted in OBPM?

In terms of career OBPM (including playoffs), no player was impacted as much as Anthony Davis (+2.3) thanks to larger rewards for scoring and less punishment for rebounding without assists. For similar reasons, Patrick Ewing (+1.8), Tim Duncan (+1.8), Andre Drummond (+1.8) and Al Jefferson (+1.8) saw rises in their offense. Big man offense is much more highly valued in BPM 2.0. Even Ben Wallace (-1.6 in old BPM) is nearly break even (-0.1) in BPM 2.0. Three of the five biggest single-season increases belong to Hassan Whiteside.

On the other hand, generic offensive guards (non creators) are not thought of as favorably in BPM 2.0. So Mario Chalmers (-1.8) and Raja Bell (-1.6) are among the biggest droppers. Another dropper is Norm Van Lier (-1.8) whose best seasons were pre-1974. Many of the largest single-season drops are clustered between 1974 and 1977 (Kevin Porter, Norm Van Lier, Jimmy Jones, Tom Boswell, Tiny Archibald, Lucius Allen) where they are probably mostly impacted by changes in the turnover estimates (player turnovers were not an official statistic until 1977-78).

Who was most-impacted in DBPM?

The biggest change here is Ben Wallace, who went from 5.6 to 2.7. He still has the fourth-best DBPM in NBA history, but the spread is compressed so his number is way down. The removal of MPG from the formula hurts big men the most. Additionally, defensive rebounds are valued less for bigs in the new formula. The biggest gainer is John Stockton, who goes from -0.9 to +1.9. Other big changes are Rudy Gobert (-2.5), Dennis Rodman (-2.4), Marcus Camby (-2.3), Larry Smith (-2.2) and Mark Eaton (-2.2).

What are the biggest changes in VORP?

For regular season and postseason combined, John Stockton's change (+44.0) is more than twice as large as any other player's change. This is because Stockton's BPM was changed more than any other player (+3.2) AND because he's one of the all-time leaders in minutes played. After these changes, he's third all-time in career VORP, which isn't as crazy as it might sound when you consider that it's a counting stat restricted to the last ~45 years and that most advanced statistics love Stockton. The next largest change is Charles Oakley (-21.9), another player with lots of minutes who does not get the same defensive credit as he did in the original formula. Other notable changes include Dirk Nowitzki (+21.6), Dennis Rodman (-18.7), Steve Nash (+17.9), Kevin Durant (+15.8), Avery Johnson (+15.7), Buck Williams (-14.0), Otis Thorpe (-13.9), Michael Jordan (+13.9), Charles Barkley (-13.8), Horace Grant (-13.8), Ben Wallace (-13.1) and Larry Smith (-13.1). A quick summation for why these changed: pure scorers and point guards were undervalued in BPM 1.0 due to interaction terms and players with high minutes but few stats are valued less in BPM 2.0. John Stockton has 9 of the 10 highest positive increases in single-season VORP.

How have the seasonal and all-time leaderboards changed?

Here's the top ten in career BPM:

Old:

  1. LeBron James 9.1
  2. Michael Jordan 8.1
  3. Charles Barkley 7.4
  4. David Robinson 7.4
  5. James Harden 7.3
  6. Larry Bird 7.2
  7. Magic Johnson 7.2
  8. Chris Paul 7.1
  9. Stephen Curry 6.5
  10. Kawhi Leonard 6.4

New:

  1. Michael Jordan 9.2
  2. LeBron James 8.9
  3. Chis Paul 7.6
  4. Magic Johnson 7.5
  5. David Robinson 7.5
  6. James Harden 6.9
  7. Larry Bird 6.9
  8. John Stockton 6.8
  9. Kawhi Leonard 6.8
  10. Kevin Durant 6.7

So Jordan moves ahead of LeBron for first. Barkley falls from the top 10 (down to 14th at 6.1). Stephen Curry also falls from the top 10 (to 11th). John Stockton and Kevin Durant move into the top 10.

Here's the top ten in single-season BPM

Old:

  1. 2017 Russell Westbrook 15.6
  2. 2009 LeBron James 13.0
  3. 1989 Michael Jordan 12.6
  4. 2016 Stephen Curry 12.5
  5. 2010 LeBron James 12.5
  6. 1988 Michael Jordan 12.2
  7. 2019 James Harden 11.7
  8. 2013 LeBron James 11.6
  9. 2020 Giannis Antetokounmpo 11.3 (in progress)
  10. 2008 LeBron James 11.2

New:

  1. 2009 LeBron James 13.2
  2. 1988 Michael Jordan 13.0
  3. 1991 Michael Jordan 12.0
  4. 2016 Stephen Curry 11.9
  5. 1989 Michael Jordan 11.9
  6. 1994 David Robinson 11.9
  7. 2010 LeBron James 11.8
  8. 2013 LeBron James 11.7
  9. 2020 Giannis Antetokounmpo 11.3 (in progress)
  10. 1993 Michael Jordan 11.2

Westbrook falls from way ahead in first place to out of the top ten. LeBron James's 2009 season improves slightly and moves from 2nd to 1st. Michael Jordan moves from two of the top ten to four of the top ten.

Here's the top ten in career OBPM

Old:

  1. LeBron James 7.2
  2. Stephen Curry 7.1
  3. James Harden 6.9
  4. Michael Jordan 6.9
  5. Chris Paul 6.4
  6. Magic Johnson 5.8
  7. Charles Barkley 5.7
  8. Damian Lillard 5.7
  9. Larry Bird 5.0
  10. Kyrie Irving 5.0

New:

  1. Michael Jordan 7.2
  2. LeBron James 7.1
  3. Kevin Durant 6.0
  4. Stephen Curry 6.0
  5. James Harden 6.0
  6. Magic Johnson 5.9
  7. Chris Paul 5.4
  8. Charles Barkley 5.4
  9. Damian Lillard 5.3
  10. Larry Bird 5.3

MJ passes LeBron to move into first. Most importantly, MJ and LeBron are in a class of their own, which feels appropriate. Durant darts up from outside the top to #3, but 3-6 is packed very tightly. Names in top ten stay same aside from Kyrie Irving dropping and Kevin Durant replacing him.

Here's the top ten in single-season OBPM

Old:

  1. 2016 Stephen Curry 12.4
  2. 2017 Russell Westbrook 10.9
  3. 2019 James Harden 10.5
  4. 1989 Michael Jordan 9.8
  5. 1988 Michael Jordan 9.8
  6. 2003 Tracy McGrady 9.8
  7. 2010 LeBron James 9.7
  8. 1990 Michael Jordan 9.7
  9. 2015 Stephen Curry 9.6
  10. 2018 James Harden 9.6

New:

  1. 2016 Stephen Curry 10.4
  2. 2003 Tracy McGrady 9.8
  3. 2009 LeBron James 9.5
  4. 2019 James Harden 9.4
  5. 2013 LeBron James 9.3
  6. 1990 Michael Jordan 9.1
  7. 2010 LeBron James 9.1
  8. 1991 Michael Jordan 8.9
  9. 1988 Michael Jordan 8.8
  10. 2014 Kevin Durant 8.8

Westbrook's 2017 drops to 12th (8.7), while Curry's 2016 remains number one. T-Mac's 2003 is supremely underrated in general, but not by this metric. Nice to see.

Here's the top ten in career DBPM

Old:

  1. Ben Wallace 5.5
  2. Manute Bol 5.3
  3. Mark Eaton 5.1
  4. Marcus Camby 4.6
  5. Rudy Gobert 4.3
  6. David Robinson 4.3
  7. Charles Jones 4.2
  8. Jim McIlvaine 4.2
  9. Tim Duncan 4.0
  10. Joakim Noah 4.0

New:

  1. David Robinson 3.1
  2. Nate McMillan 2.9
  3. Mark Eaton 2.9
  4. Ben Wallace 2.8
  5. Draymond Green 2.8
  6. Marcus Camby 2.7
  7. George Johnson 2.6
  8. Bo Outlaw 2.6
  9. Tree Rollins 2.5
  10. Hakeem Olajuwon 2.5
  11. Kawhi Leonard 2.4 (mentioning due to his current relevance)

Most notable trend here is that everything is far more compressed defensively. Many of the names in the top ten remain the same, but the overall impact is down. It should also be noted that defensive BPM is necessarily less likely to be precise since the box score measures for defense are far inferior to the offensive inputs. It's nice to see versatile defenders like Nate McMillan, Draymond Green, Hakeem Olajuwon and Kawhi Leonard in the new top ten.

Here's the top ten in single-season DBPM

Old:

  1. 2003 Ben Wallace 7.0
  2. 2018 Ekpe Udoh 6.8
  3. 2004 Ben Wallace 6.8
  4. 2007 Ben Wallace 6.8
  5. 2007 Marcus Camby 6.7
  6. 2008 Marcus Camby 6.6
  7. 2002 Ben Wallace 6.5
  8. 1986 Manute Bol 6.4
  9. 2006 Ben Wallace 6.4
  10. 1989 Mark Eaton 6.1

New:

  1. 1994 Nate McMillan 5.5
  2. 2010 Marcus Camby 5.5
  3. 2012 Marcus Camby 4.9
  4. 1986 Manute Bol 4.7
  5. 1992 David Robinson 4.6
  6. 1987 Manute Bol 4.6
  7. 2008 Ben Wallace 4.4
  8. 1983 Mark Eaton 4.3
  9. 1985 Mark Eaton 4.2
  10. 1988 Michael Jordan 4.2

Here's the top ten in career VORP

Old:

  1. LeBron James 134.4
  2. Michael Jordan 104.4
  3. Karl Malone 102.5
  4. Kevin Garnett 94.0
  5. Charles Barkley 93.5
  6. Tim Duncan 89.3
  7. Kareem Abdul-Jabbar 86.0 (partial number since career began pre-74)
  8. Chris Paul 81.2
  9. David Robinson 80.9
  10. Larry Bird 80.0

New:

  1. LeBron James 132.2
  2. Michael Jordan 116.1
  3. John Stockton 106.5
  4. Karl Malone 99.0
  5. Kevin Garnett 96.6
  6. Tim Duncan 91.1
  7. Kareem Abdul-Jabbar 85.7 (partial number since career began pre-74)
  8. Chris Paul 85.3
  9. Dirk Nowitzki 84.8
  10. David Robinson 82.0

Big changes are John Stockton and Dirk Nowitzki moving into the top ten, while Charles Barkley falls from fifth to 11tth, and Larry Bird drops from tenth to 15th. Also, LeBron James's edge over Jordan is no longer nearly as significant.

Here's the top ten in single-season VORP

Old:

  1. 2017 Russell Westbrook 12.4
  2. 1989 Michael Jordan 12.0
  3. 1988 Michael Jordan 11.8
  4. 2009 LeBron James 11.6
  5. 2010 LeBron James 10.9
  6. 1994 David Robinson 10.6
  7. 1976 Kareem Abdul-Jabbar 10.5
  8. 2008 LeBron James 10.1
  9. 1990 Michael Jordan 10.1
  10. 2009 Chris Paul 10.0

New:

  1. 1988 Michael Jordan 12.5
  2. 2009 LeBron James 11.8
  3. 1989 Michael Jordan 11.4
  4. 1994 David Robinson 11.4
  5. 1991 Michael Jordan 10.8
  6. 1990 Michael Jordan 10.6
  7. 1987 Michael Jordan 10.6
  8. 2010 LeBron James 10.3
  9. 1993 Michael Jordan 10.2
  10. 2004 Kevin Garnett 10.0

Westbrooks falls from first to 22nd, which seems more sane. It also seems very sane that Michael Jordan and LeBron James dominate the new list.

We'd once again like to thank Daniel Myers for his excellent work with this statistic and we hope you enjoy it!

3 Responses to “Introducing BPM 2.0”

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  3. Nick p Says:

    Damn y'all really went and messed up the entire system. BPM and Vorp was the most accurate all in one stat available and you tweaked it to the point of unrecognition. I mean its common sense. There is no argument to be made that stockton had a more valauble career than tim duncan, malone and garnett and he certainly was not more valuable from game to game. You must've completely over valued steals. Curry gets a lot of steals too and hes still not a good defender. Duncan and garnett were all world 2 way players who dominated for their teams and won championships. If your new numbers were even remotely accurate then the pairing of stockton and malone would have won multiple championships. This is just silly.

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