Dictionary.com tells us that the word “overrated” means: to rate or appraise too highly; overestimate
The word “high” is a relative term. To argue that something is “too high” or “too low” requires a reference point. Actually, to be precise, you need two points of reference.
For example, batting average in baseball will overestimate a player’s contribution if that player fails to draw walks and/or can’t hit for power. If we wish to argue that batting average overestimates a player’s contribution we must note where a player is ranked in terms of batting average and also where he is ranked in terms of a measure that considers plate discipline and power (i.e. OPS). In sum, we need two metrics to make the “overrated” argument.
Batting average has been calculated in baseball since the 19th century and it remains the most cited measure of a hitter’s effectiveness (one only needs to watch a baseball game on TV to see this point). When we turn to basketball, the “batting average statistic” (i.e. oldest and most cited) is points scored per game.
As we note in The Wages of Wins (and/or in this forum), this single metric does a remarkably good job of explaining the player evaluations of the coaches, general managers, and the sports media. And just like batting average, points scored per game is obviously not a perfect measure.
Focusing just on scoring ignores other factors that contribution to wins (such as rebounds, turnovers, steals, etc…). Scoring totals can also be inflated with more minutes and/or more shot attempts. In other words, lofty scoring totals may not coincide with scoring efficiency. Despite these shortcomings, scoring totals still dominate the discussion of a basketball player’s value.
Three Perspectives on the Overrated
The topic today is “overrated”, and as noted above, we need two reference points to tackle this subject. And given that this is The Wages of Wins Journal, the second reference point we will consider is Wins Produced. Specifically – as detailed in Table One — we are going to first look at how players rank in terms of both Wins Produced and points-per-game.
Table One reports the 15 players who are the most overrated by scoring. At the top of the list is Al Harrington. Of the 128 players who played at least 2,000 minutes in 2008-09, Harrington ranked 22nd in points per game. As detailed more than once in this forum (at least, I think more than once), Harrington has never offered much beyond scoring. Consequently, with respect to Wins Produced he ranks quite low (124 out of 128).
Although points-per-game is frequently cited, there are of course more sophisticated metrics that try and take into account more of what a player does on the court. One of the oldest (and again, commonly cited) of these metrics is NBA Efficiency. This measure is calculated as follows:
NBA Efficiency = Points + Rebounds + Steals + Assists + Blocked Shots – All Missed Shots – Turnovers
Table Two looks at the most overrated players according to this measure.
Again our second point of reference is Wins Produced. And again we see Al Harrington topping the list. Joining Harrington on both lists are Andrea Bargnani, Jeff Green, O.J. Mayo, Richard Jefferson [most overrated in 2007-08], Rudy Gay, and Stephen Jackson.
The similarities between the two evaluations are not surprising. The correlation coefficient between these two metrics for the 2008-09 season is 0.89 (NBA Efficiency per game and points scored per game has a 0.93 correlation).
Of course NBA Efficiency is not very sophisticated. This metric essentially adds together a player’s positive actions and subtracts off the negative. What happens if we turn to a measure that attempts to weight each player’s actions?
The most popular weighted measure is John Hollinger’s Player Efficiency Rating (PER). The simple version (okay, much simpler) of the PER metric – Game Score – indicates the basic weights employed.
Game Score = Points + 0.4*Made Field Goals – 0.7*Field Goal Attempts – 0.4*Free Throws Missed + 0.7*Offensive Rebounds + 0.3*Defensive Rebounds + Steals + 0.7*Assists + 0.7*Blocked Shots – 0.4* Personal Fouls – Turnovers
For 2008-09, Game Score and NBA Efficiency have a 0.99 correlation (this is basically what we find in other years as well). PER is a per-minute metric, and it has a 0.99 correlation with Game Score per-minute. Given the high correlation between these measures, we shouldn’t expect much difference in our list of overrated.
Before we get to the results, though, we need to note that since PER is a per-minute measure our second reference point has to be WP48 [Wins Produced per 48 minutes]. Despite this change, we still see some familiar names. Once again we see Al Harrington, Rudy Gay, Stephen Jackson, Allen Iverson, Danny Granger, David West, Jamal Crawford, Mehmet Okur, and Richard Hamilton. Harrington, though, doesn’t lead the list of overrated when we compare PER and WP48. Now Michael Beasley tops the list. Yes, this is the same Beasley that John Hollinger says is just as productive as Carlos Boozer (I might offer an entire post on that claim).
The Most Overrated
Although Beasley tops the PER list, he is not the most overrated if we consider all three rankings. If we add together the differences from each comparison the most overrated player in the NBA for 2008-09 is….. yes, Al Harrington. Here are the 15 most overrated players if we consider all three perspectives.
- Al Harrington
- Rudy Gay
- Stephen Jackson
- Andrea Bargnani
- Danny Granger
- David West
- Mehmet Okur
- Richard Jefferson
- Jamal Crawford
- Jermaine O’Neal
- Charlie Villanueva
- Jeff Green
- Richard Hamilton
- Thaddeus Young
- Michael Beasley
One should be clear that “overrated” does not necessarily mean “bad.” Granger and West were above average players [in terms of WP48] this past season. These players just weren’t as good as the scoring based metrics suggest.
For those who want more on this topic, you can see a discussion of past seasons in Chapter 10 of The Wages of Wins. For more on NBA Efficiency, PER, and Game Score, please see the following posts:
NBA Efficiency: Do We Overvalue Rebounds? (November 9, 2006).
PER: A Comment on the Player Efficiency Rating (November 17, 2006)
Game Score: Marvin Williams Makes a Hypothetical Deal (December 16, 2007)
Two more notes:
1. For the WP48 numbers offered in this post, player performance was compared to the exact position played (i.e. center, power forward, etc…). Over the past year or so in this forum I have only been considering three positions (big men, small forward, guards). But the numbers used for this post came from a spreadsheet where averages from all five positions were used, so some differences will be observed if you compare these results to past postings.
2. I also took most of the text for this post from what I said about the Most Overrated Players in 2007-08. In other words, much of this post is a re-run. This seems appropriate since there were players (Richard Jefferson, Rudy Gay, Stephen Jackson, Jamal Crawford, and David West) who managed to repeat an appearance on the overrated list.
In case anyone was interested, here are the next five “overrated” players:
16. O.J. Mayo
17. LaMarcus Aldridge
18. Carmelo Anthony
19. Ben Gordon
20. Wilson Chandler
Given that I am a Pistons fan, I thought I would note that the Pistons spent their free agent money on two players ranked in the top 20 on the “overrated” list. Meanwhile, some very good teams have been shopping from the “underrated” list (which I will post soon).
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Our research on the NBA was summarized HERE.
Wins Produced, Win Score, and PAWSmin are also discussed in the following posts:
Finally, A Guide to Evaluating Models contains useful hints on how to interpret and evaluate statistical models.