Tag: analytics

The GOAT Ladder Part 8: #215-211

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 8: #215-211” →
 

The GOAT Ladder Part 7: #220-216

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 7: #220-216” →
 

The GOAT Ladder Part 6: #225-221

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 6: #225-221” →
 

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” →
 

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
Continue reading “What is TPA?” →
 

Matchup-Based Defense

Defense is the unsolvable puzzle in NBA analytics. No matter how advanced the advanced stats get, defensive metrics continue to crash against the same conundrums. Better data often leads to better models, and recent years have seen a dramatic improvement in the quality of defensive data available for analysis. Tracking data, opponent shooting data, play-by-play data, and more have all played a hand in modern defensive analysis. In spite of the improvements, or perhaps in part because of the improvements, it is clear that defensive analysis is still not highly accurate.

Most defensive metrics which are currently extant are based on one of two schools of thought. In order to take stock of why defensive analysis is still frequently inaccurate, it will help to investigate the underlying assumptions behind most current models.

The Plus/Minus School of Thought

The most popular method by far is The Plus/Minus School, which counts BPM, RPM, RAPM, PIPM, and more among its adherents. The distinguishing precept of the Plus/Minus School is the belief that we can ascertain a player’s defensive value by evaluating the team’s performance with him on the court, if only we properly adjust for strength of opponent, the team’s talent level, the team’s performance with the player off the court, and the player’s performance level in seasons past. The adjustments made to raw plus/minus are attempts to extract reliable data by excising confounding variables.

Continue reading “Matchup-Based Defense” →