Undervaluing the Denominator

Posted on November 6, 2007 by


Last year 458 players took the floor in the NBA.  Given all the people playing college basketball and basketball in other nations, the percentage that reach the Association is truly quite small.  So it’s not surprising when very, very good players don’t quite make the cut.  Still, if a player is significantly more productive than the average NBA player at his position you would expect a home in the NBA to found someplace.  At least, that’s what Jamal Sampson should expect if the NBA didn’t systematically “undervalue the denominator.”  What does it mean to “undervalue the denominator”?  And who the hell is Jamal Sampson? 

Let me answer the second question first.

The Jamal Sampson Story

Here is part of Sampson’s bio from NBA.com:

Height: 6’11

Weight: 235

Position: Forward-Center

Is the cousin of former NBA All-Star Ralph Sampson.

As a senior at Mater Dei High School, averaged 15.5 points, 10.0 rebounds and 2.4 blocks.

Led team to the California state championship with a 57-54 victory over Modesto Christian.

Mater Dei finished the 2000-01 season with a 33-2 record and a No. 4 national ranking from USA Today.

Rated the nation’s No. 15 recruit by Foxsports.com and the No. 1 center on the West Coast by Rivals.com.

Also ranked No. 26 overall by The Sporting News and No. 21 by CBSSportsline.com.

Missed several games his senior season with bone spurs, but had corrective surgery during summer of 2001.

As a freshman at California, appeared in 32 games, averaging 6.4 points, 6.5 rebounds and 1.7 blocks.

Played one season at California.

Named to the Pac-10 All Freshman Team.

An early entry candidate for the 2002 NBA Draft.

So the cousin of Ralph Sampson was highly regarded coming out of high school.  He played one season at California, where he posted a Win Score per minute of 0.188, which is well below average.  Still he was taken with the 46th pick in the 2002 NBA draft.  And then the journey began.  Here are the stops in his career and the minutes logged in each location.

2002-03: Milwaukee (8 minutes)

2003-04: LA Lakers (130 minutes)

2004-05: Charlotte (329 minutes)

2005-06: Sacramento (39 minutes)

2006-07: Denver (124 minutes)

In the 2007 pre-season Sampson was employed by the Dallas Mavericks.  But the dream ended on October 22nd.

So six teams have had a chance to employ Sampson, and six teams have passed on his services.  Clearly he’s not a very productive player.  

Well, at least that is what we might think if we didn’t look at the numbers.  When we look at what Sampson has done in the NBA, it appears he has something to offer. Here is his Wins Produced per 48 minutes [WP48] for each of the teams that have employed him in the regular season:

Milwaukee: 0.036

LA Lakers: 0.309

Charlotte: 0.190

Sacramento: 0.678

Denver: 0.247

An average player posts a WP48 of 0.100.  With the exception of the 8 minutes he played in Milwaukee, Sampson has clearly been above average at each stop in his career.

When we look at Sampson’s career stats – which are reported in Table One — we can see why he is so productive.

Table One: Jamal Sampson’s Career

Sampson is virtually average with respect to shooting efficiency, blocked shots, and assists.  He is below average with respect to scoring, steals, and personal fouls.  But he is above average with respect to turnovers and rebounds.  In fact, his rebounding numbers are way above average. 

Per 48 minutes Sampson grabs 18.4 rebounds.  In 2006-07, only Reggie Evans and James Augustine bested this rate, and Augustine only played 7 minutes. If we go back to 1991-92, this rebounding rate compares to players named Dennis Rodman, Danny Fortson, Ben Wallace, and Dikembe Mutombo.  Yes, in the 630 minutes Sampson has played in his career he has demonstrated that he is an elite rebounder.

Undervaluing the Denominator

He is also unemployed. Soon after Sampson left the Mavericks, Dallas signed Juwan Howard.  As Table Two indicates, Howard is the anti-Sampson. 

Table Two: Juwan Howard’s Career

Howard has demonstrated in his career that he can score and get assists at an above average rate. But Howard is below average with respect to shooting efficiency, rebounds, steals, blocked shots, and turnovers.  And not surprisingly, well below average with respect to Win Score (a point I have made before about Howard).  Despite this inefficiency, Howard has been paid $130 million in his career and he had no trouble finding a job on a title contender when the T-Wolves decided to focus on youth this year.

Now it’s not the case that the Mavericks cut Sampson to sign Howard.  Sampson was long gone before Howard was added to the roster.  Still, one wonders what the Mavericks would look like with Sampson playing a few minutes each night.  Certainly he could help this team weather the current injury to Erick Dampier.

Of course it’s possible there is something wrong with Sampson that the data doesn’t reveal. Maybe he’s a lousy defender.  Maybe he routinely abuses his coaches. Maybe he wears the wrong shoes.  But his story does seem to highlight a basic bias in the evaluation of talent. 

Wins in the NBA are determined by a team’s offensive and defensive efficiency. Each efficiency metric is a ratio of scoring to possessions. Those who excel at the numerator – like Juwan Howard – have long careers and collect obscene sums of money.  And this is true, even if Howard’s inability to hit shots and rebound means he has actually diminished the chance of his team being successful. 

Players who excel at factors listed in the denominator – like Jamal Sampson (and Anderson Varejao) – have trouble getting a job and/or consistently finding time on the court.  The evidence seems quite clear that the denominator is undervalued in the NBA.  Although both getting (and keeping) the ball help a team win, those who excel at this activity are often shown the door.

So what is the lesson for young basketball players:  Being a scorer – even if you aren’t really that efficient – gets you a job and gets you paid.  Live in the denominator, though, and you will drift from job to job.  And that’s true, even if the numbers say you are well above average.

By the way, before we all feel too sorry for Jamal Sampson, we should note that Basketball-Reference indicates he has been paid $3 million during his NBA career. Yes, that ain’t $130 million.  But that’s pretty good money for 630 minutes. 

– DJ

Our research on the NBA was summarized HERE.

The Technical Notes at wagesofwins.com provides more information on the published research behind Wins Produced and Win Score

Wins Produced, Win Score, and PAWSmin are also discussed in the following posts:

Simple Models of Player Performance

Wins Produced vs. Win Score

What Wins Produced Says and What It Does Not Say

Introducing PAWSmin — and a Defense of Box Score Statistics