Measuring Bad NBA Players and the Worst NBA Player of All Time
Talking about a bad NBA Player is kind of a weird thing. Even the worst NBA player of all time is among the best basketball players of all time. Talking about the worst of the best is always a loaded discussion. But we’re still going to do it.
In this article, we’re going to look all the way back to the 1974 NBA season to find those players that really were bad NBA players. This includes finding out who the Worst NBA Player of All time is.
We’re going to look at the list of bad NBA players by using advanced stats. To be the worst, you not only had to be significantly below average. You had to do it for a long time, too. Using advanced stats lets us look at the worst NBA player of all time on both the offensive and defensive side of the ball as well. We’ll also look at the worst individual seasons of all time.
What it Means to be the Worst NBA Player of All Time
Measuring bad NBA players, especially the worst NBA player of all time, is a surprisingly difficult problem.
If a player is too bad, they drop out of the league. The really bad players don’t stay NBA players for very long. Finding the worst NBA player of all time requires finding the player that was
- Just good enough to stay in the league and actually see the court for meaningful minutes while
- Still being really bad on the court.
When we talked previously about the age old Lebron v. Jordan debate, a common idea was that the best players in the league should be those that are really good for a long time. In exactly the same way, the worst NBA player of all time needs to be really bad for a long time.
The metric we will use to determine the truly bad NBA players is how much negative impact they accrued over the course of a season or a career. Accruing lots of negative impact requires being bad while on the court AND being on the court for a lot of minutes.
In this way, our metric for bad NBA players will be based on those players that were the most detrimental to their teams.
Our Metric for Bad NBA Players
To measure NBA player impact, we use box plus/minus which is a stat that describes a player’s contribution to their team’s margin of victory. BPM is also traditionally split into offensive and defensive components. A player’s overall contribution to margin of victory is the sum of their offensive and defensive contributions.
BPM is a player’s contribution to their team’s margin “per 100 possessions”. For example, a -2 BPM would indicate that over 100 possessions, a player made his team 2 points worse. Among players with similar BPMs, those who played more minutes and more possessions had a larger net negative impact on their team because they were on the court more.
Our metric for determining bad NBA players is to multiply possessions played by their BPM number. The result is a total estimate of a player’s net negative contributions to their team’s margin across all time they were on the court. The most negative numbers are those players who lost their team the most points. This is how we’ll measure the worst NBA player of all time.
To quickly check whether this makes sense as a metric, we can look at who the BEST players of all time are by this metric. We did this and ran the numbers. The results were that the two best players according to the metric are Lebron James and Michael Jordan. This is a sign that our metric works pretty well.
In the next sections, we’ll simply call this metric net plus-minus to indicate that it is a total value.
Worst NBA Player of All time, Season by Season
A first way to look at the data is to understand what level of performance typically corresponds to the worst in a season. The histogram below shows the distribution of worst net plus-minus scores for each season since 1974.
This histogram shows that in a typical season, the worst player contributes somewhere between -30 and -60 net plus-minus. This means that the player hurt their team for 30 to 60 points over the course of the season.
One number stands out in the above table. There is a single season where a player contributed worse than a -70 net plus-minus to their team. The single worst all time NBA season belongs to Michael Olowokandi in his 2000 campaign with the spurs.
In 2000, Michael Olowokandi had a BPM of -6. This means that he hurt his team by about 6.5 points per game! That is a massive number. The real reason his season was the all time worst NBA season was because he played so many minutes. In the 2000 season, Olowokandi played 1 more minute than Shawn Kemp and 30 more minutes than TMac. All while being a huge net negative.
Michael Olowokandi tops the list of bad NBA players for an individual season. Shown below is the rest of the top 5. We also broke down the data by worst offensive and defensive seasons.
Before moving on, I have a few more comments about this list. If we look closely, this isn’t entirely a list of bad NBA players. Most notably, Moses Malone (!!) shows up as having one of the worst all-time defensive seasons in 1980.
I will also point out that a lot of the players on this list are rookies or very young players. This makes sense, though, given our metric. Rookies tend to be much worse than their veteran counterparts. However, teams are willing to give them lots of playing time with the expectation of improved performance. This can often lead to significant, sustained negative impact.
The previous data was bad NBA players over the course of a single season. What if we look at a career?
The Worst NBA Player of All Time
In the previous section, a lot of people who showed up on the worst NBA player of all time list were rookies. Rookies get lots of playing time without needing to be good. But when we look at a career and the really bad NBA players, things get more interesting.
It is actually hard to be really bad for a really long time. You need to do one of two things to end up on this list:
- Be really, really bad for a few seasons
- Be kind of bad for a long career
The first option runs the risk of being too bad, though. If you have more than two or three significantly below average seasons in a row, you might end up falling out of the league. At the very least, you’ll run the risk of losing playing time.
However, there always has to be a worst NBA player of all time. We went through every season and every player since the mid 1970s and looked at their stats. We tallied up their possessions played and their BPM stats and added up their career contributions. The table below shows those players who hurt their teams the most over the course of their careers.
The top 5 worst NBA players of all time by our metric are Kevin Willis, Kevin Duckworth, Joe Kleine, Juwan Howard, and Austin Rivers. Each of these guys hurt their team to the tune of over 300 points.
To put that into perspective, these guys basically turned 50 1 point wins into 50 5 point losses by virtue of their play. Thinking of things in that way makes it a lot more significant.
Some Comments
The first thing that stands out to me is that Kevin Willis is often thought of as a terrible player. He holds the all time record for most games played without being in the hall of fame. So for him, he wins the worst NBA player of all time record by virtue of being a bit below average for a long time. The same is true for Kevin Duckworth, who actually made 2 all star teams. Not kidding.
Joe Kleine played a mid amount of minutes for a long time while barely accruing noticeable stats. Juwan Howard is commonly recognized as a good player. But go look at his basketball reference page. He was a fairly significant net negative player who played a ridiculous amount of minutes. This leads to a really large net negative team impact.
Some of the other names on the list are interesting, especially the worst defensive players of all time. Eddie Johnson is a pretty stereotypical sixth man; a good offensive and bad defensive player. Moses Malone was another product of being bad on defense and banking lots of minutes.
