The GOAT Ladder Part 5: #230-226

Who is the greatest NBA player of all time? I will be seeking the NBA GOAT in a series of posts featuring wide-ranging descriptions of the top 250 players in league history. For an explanation of what the stats I’ll be using mean, read the five-part intro starting here and continuing in Part 2, Part 3, Part 4, and Part 5. For each player on the ladder, from #250 to #1, I’ll be including three key graphics (plenty of other views will appear throughout, but these three will be in every write-up):

  1. Grades – Percentile values for the player’s rank among all players in NBA history. They are explained further in Part 5 of the intro.
  2. ON_GOD – A per-game expression of a player’s impact on both offense and defense. ON_GOD is described in Part 4 of the intro.
  3. Z-Scores – A score that standardizes a player’s contribution to allow for comparison across eras. Part 3 of the intro explains D_SCORE, and Part 2 outlines O_SCORE.

Above these graphics, I will report two measurements for each player: his GPA (the average of his grades from the “Report Card”) and career awards. I have gone through and retroactively assigned awards for every NBA season since 1952-53 (the first season for which data is relatively complete). The awards listed here are a record of who I think should have won them, not a record of who actually won them.

If you’re curious about comparing these players with others, you can find both basic box score stats and my suite of advanced stats from the Stats page, or simply by using the “Stats” dropdown menu at the top of the page.

Continue reading “The GOAT Ladder Part 5: #230-226”
 

The GOAT Ladder Part 4: #235-231

Who is the greatest NBA player of all time? I will be seeking the NBA GOAT in a series of posts featuring wide-ranging descriptions of the top 250 players in league history. For an explanation of what the stats I’ll be using mean, read the five-part intro starting here and continuing in Part 2, Part 3, Part 4, and Part 5. For each player on the ladder, from #250 to #1, I’ll be including three key graphics (plenty of other views will appear throughout, but these three will be in every write-up):

  1. Grades – Percentile values for the player’s rank among all players in NBA history. They are explained further in Part 5 of the intro.
  2. ON_GOD – A per-game expression of a player’s impact on both offense and defense. ON_GOD is described in Part 4 of the intro.
  3. Z-Scores – A score that standardizes a player’s contribution to allow for comparison across eras. Part 3 of the intro explains D_SCORE, and Part 2 outlines O_SCORE.

Above these graphics, I will report two measurements for each player: his GPA (the average of his grades from the “Report Card”) and career awards. I have gone through and retroactively assigned awards for every NBA season since 1952-53 (the first season for which data is relatively complete). The awards listed here are a record of who I think should have won them, not a record of who actually won them.

If you’re curious about comparing these players with others, you can find both basic box score stats and my suite of advanced stats from the Stats page, or simply by using the “Stats” dropdown menu at the top of the page.

Continue reading “The GOAT Ladder Part 4: #235-231”
 

The GOAT Ladder Part 3: #240-236

Who is the greatest NBA player of all time? I will be seeking the NBA GOAT in a series of posts featuring wide-ranging descriptions of the top 250 players in league history. For an explanation of what the stats I’ll be using mean, read the five-part intro starting here and continuing in Part 2, Part 3, Part 4, and Part 5. For each player on the ladder, from #250 to #1, I’ll be including three key graphics (plenty of other views will appear throughout, but these three will be in every write-up):

  1. Grades – Percentile values for the player’s rank among all players in NBA history. They are explained further in Part 5 of the intro.
  2. ON_GOD – A per-game expression of a player’s impact on both offense and defense. ON_GOD is described in Part 4 of the intro.
  3. Z-Scores – A score that standardizes a player’s contribution to allow for comparison across eras. Part 3 of the intro explains D_SCORE, and Part 2 outlines O_SCORE.

Above these graphics, I will report two measurements for each player: his GPA (the average of his grades from the “Report Card”) and career awards. I have gone through and retroactively assigned awards for every NBA season since 1952-53 (the first season for which data is relatively complete). The awards listed here are a record of who I think should have won them, not a record of who actually won them.

If you’re curious about comparing these players with others, you can find both basic box score stats and my suite of advanced stats from the Stats page, or simply by using the “Stats” dropdown menu at the top of the page.

Continue reading “The GOAT Ladder Part 3: #240-236”
 

The GOAT Ladder Part 2: #245-241

Who is the greatest NBA player of all time? I will be seeking the NBA GOAT in a series of posts featuring wide-ranging descriptions of the top 250 players in league history. For an explanation of what the stats I’ll be using mean, read the five-part intro starting here and continuing in Part 2, Part 3, Part 4, and Part 5. For each player on the ladder, from #250 to #1, I’ll be including three key graphics (plenty of other views will appear throughout, but these three will be in every write-up):

  1. Grades – Percentile values for the player’s rank among all players in NBA history. They are explained further in Part 5 of the intro.
  2. ON_GOD – A per-game expression of a player’s impact on both offense and defense. ON_GOD is described in Part 4 of the intro.
  3. Z-Scores – A score that standardizes a player’s contribution to allow for comparison across eras. Part 3 of the intro explains D_SCORE, and Part 2 outlines O_SCORE.

Above these graphics, I will report two measurements for each player: his GPA (the average of his grades from the “Report Card”) and career awards. I have gone through and retroactively assigned awards for every NBA season since 1952-53 (the first season for which data is relatively complete). The awards listed here are a record of who I think should have won them, not a record of who actually won them.

If you’re curious about comparing these players with others, you can find both basic box score stats and my suite of advanced stats from the Stats page, or simply by using the “Stats” dropdown of the menu at the top of the page.

Okay, that’s enough preparation. Let’s get this train rolling!

Continue reading “The GOAT Ladder Part 2: #245-241”
 

The GOAT Ladder Part 1: #250-246

Who is the greatest NBA player of all time? I will be answering that very question in a series of posts featuring wide-ranging descriptions of the top 250 players in NBA history. For an explanation of what the stats I’ll be using mean, read the five-part intro starting here and continuing in Part 2, Part 3, Part 4, and Part 5. For each player on the ladder, from #250 to #1, I’ll be including three key graphics (plenty of other views will appear throughout, but these three will be in every write-up:

  1. Grades – Percentile values for the player’s rank among all players in NBA history. They are explained further in Part 5 of the intro.
  2. ON_GOD – A per-game expression of a player’s impact on both offense and defense. ON_GOD is described in Part 4 of the intro.
  3. Z-Scores – A score that standardizes a player’s contribution to allow for comparison across eras. Part 3 of the intro explains D_SCORE, and Part 2 outlines O_SCORE.

Above these graphics, I will report two measurements for each player: his GPA (the average of his grades from the “Report Card”) and career awards. I have gone through and retroactively assigned awards for every NBA season since 1952-53 (the first season for which data is relatively complete). The awards listed here are a record of who I think should have won them, not a record of who actually won them.

If you’re curious about comparing these players with others, you can find both basic box score stats and my suite of advanced stats from the Stats page, or simply by using the “Stats” dropdown of the menu at the top of the page.

Okay, that’s enough preparation. Let’s get this train rolling!

Continue reading “The GOAT Ladder Part 1: #250-246”
 

Beyond the Box Score

It is time to stop evaluating players based on statistical feats. The ubiquity of statistical data has brought with it a ready supply of historical comparisons. In today’s NBA, one can hardly turn around without running into a stat trumpeting a player as “the first player since MJ to have 18 consecutive games of 20-5-5”. Who can ignore the box score aggregators, with their perpetual lists of “top performances of the night” that are oriented mainly around points, rebounds, and assists? The basketball community is awash in counting stats-based evaluations, but it’s time to cut it out.

The comeuppance has been a long time coming, to be perfectly honest. Fans have long prized points, rebounds, and assists as basketball’s version of the “Triple Crown” – a trio of statistics that can combine to depict a player’s value. Such an outcome is to be expected, since those three statistics are usually the largest numbers in any box score; our eyes are drawn to big numbers. In The Book of Basketball, Bill Simmons concretized the method of measuring players by Points+Rebounds+Assists in constructing his all-time rankings, which certainly did nothing to cool the ardor of counting stat acolytes.

It Was Never a Good Idea

Adding together counting stats was a bad idea to begin with. Taking values that describe discrete events and adding them without modification is among the poorest methods of measuring a player’s impact. Every box score statistic (every statistic period, as a matter of fact) exists on a certain scale. While it is quite common for a player to score 10 points in a game, and somewhat common for a player to grab 10 rebounds in a game, it is decidedly uncommon for a player to register 10 steals in a game. The scale – or range of normal values – for steals is much smaller than the scale for points. Since points, rebounds, and assists each have their own scale, adding them is always going to privilege points above the other components.

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What is TPA?

by Alan Moghaddam

Chances are if you’re into sports you’ve seen the famed charts from @NBA_Math that feature overlapping pictures of NBA players in a conventional Cartesian plot with a line plotted on it (y=-x). Anything above the line is good, anything below is bad, and average values will tend to walk the line. The graph is a visual attempt to quantify some mystery statistic known as TPA.

This is a standard TPA graph from @NBA_Math

What is TPA?

This is something of a loaded question; the acronym TPA stands for “Total Points Added”. The basic idea behind it is that a player adds points on offense and defense. You then total these subsections to get TPA.

Unfortuantely, the definition above is rather incomplete. We now need to understand Offensive Points Added (OPA) and Defensive Points Saved (DPS), the components which make up TPA. The two subcategories are much more complex than TPA alone.

To get OPA and DPS, we need to use “Box Plus/Minus,” an all-in-one statistic created by Daniel Myers and hosted at basketball-reference.com. I promise we are almost at the bottom of the well here in terms of stat definitions. Box Plus/Minus is a relativistic stat that gauges a player’s impact on team performance when s/he is on the court. S/he again will have an impact on both defense and offense, so accordingly Box Plus/Minus can break down into two stats: Offensive Box Plus/Minus (OPBM) and Defensive Box Plus/Minus (DPBM). We can already see that TPA has the same structure as Box Plus Minus; both purport to measure a player’s impact on both ends of the floor. What is the difference between the two?

Equation 1. Calculation of TPA as a function of Defensive Points Saved and Offensive Points Awarded
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The Best Defensive Small Forwards in the NBA

In the last installment of this series, we evaluated the best defensive shooting guards. We noted that the shooting guard group is crucial in the modern NBA due to the advantages gained by employing versatile defenders capable of stopping opponents of different sizes and skill sets. The same rationale applies for the players in the “small forward” bin using basketball-reference.com’s play-by-play position designations. When compared with the previous group, the main difference is that the small forwards are larger. (perhaps we should start calling them “big wings”?)

Wings, whether they are categorized as “shooting guards” or “small forwards,” exhibit greater spread in the defensive load they carry than other position groups do.

While the median values are relatively consistent across positions, wings have a wider distribution than other positions. Raw defensive load for wings can range from very high (>15 ppg) to very low (<6 ppg). Other positions, especially interior defenders, have much more compressed distributions.

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Who Are the Best Defensive Shooting Guards in the League?

The NBA changes as rapidly as the seasons, and the league is heading toward a greater and greater reliance on versatile perimeter players. The prevalence of 3-pointers, combined with the emergence of bigger primary ball handlers replacing some of the smaller “point guards” of previous eras, has resulted in a single mandate for NBA defenses: to find defenders who are big enough and quick enough to guard anyone.

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Who are the Best Defensive Point Guards in the NBA?

Rankings are among the most popular exercises for most NBA fans, and also among the least efficient ways to evaluate data. The enduring appeal of rankings and lists owes to their relationship, however tangential, with the big questions: Who is the best? Which player is better? How much better or worse would a team be if they replaced this player with that one? Every fan, analyst, scout, coach, and executive needs to be able to answer these questions.

The problem with rankings is not the questions they address, but the biases implicit in ordinal numbering. Our brains are trained to think that the difference between 12 and 17 is the same as the difference between 18 and 23, and that all these values are on a different order of magnitude from single digit numbers. When we transfer these assumptions to rankings of the “Top 50 Players in the NBA” or something similar, we start with false presuppositions. There is not an identical difference in value between each pair of contiguous players on any player ranking. Even a hypothetically perfect, pie-in-the-sky ranking that ranked players in the exactly correct order would still need something besides the ranking to indicate the players’ true value relative to their peers. Our habit of using ordinal numbers to rank players blinds us to the shape of the data.

As a result, both league insiders and outsiders spend an inordinate amount of time debating questions such as “Is Kevin Durant the second-best player in the league or the eighth-best?” “Is Paul George a top 5 player, a top 10 player, or a top 15 player?” What really matters is how much a player contributes to wins by helping put points on the board (on offense) and keep points off the board (on defense). If the 6th ranked player in the league and the 16th ranked player are nearly identical in terms of their contribution to team success, it makes little sense to lay so much weight on their difference in the rankings.

What a valuable ranking system can tell us is how much value a player generates, relative to the rest of the population. In answering the question posed in the title of this article, I will attempt to provide enough context for the reader to be able to comprehend the shape of the data. As such, let’s start with refining the question itself:

Who are the best defensive point guards in the league?

Continue reading “Who are the Best Defensive Point Guards in the NBA?”