The Ethical Hooper Index: NBA Scoring, Skill vs. the Whistle

✓ Completed · November 2026

An R and Quarto study of 30 NBA seasons and 6.3 million shots that turns basketball slang into a measurable index, ranks every qualifying scorer since 1996-97, and tests it against the NBA’s 2021-22 crackdown on foul-baiting.

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The question

“Ethical hooper” is basketball slang for a player who scores through pure skill (clean footwork, natural shot-making, smooth handles) rather than foul-baiting, flopping, or jumping into defenders to draw a whistle. I wanted to know whether that idea could be measured. Who are the most and least “ethical” scorers since 1996-97? And when the NBA told referees in 2021-22 to stop rewarding “non-basketball moves,” did it hit the players my index had flagged?

What I did

• Built the dataset from 30 seasons of NBA play-by-play and shot charts (1996-97 to 2025-26, regular season and playoffs): 6.3 million shots and every foul and free throw, linked to official minutes and positions from Basketball Reference.
• Validated it against independent sources. My counts of shooting fouls drawn, and-ones, offensive fouls and assisted shots match Basketball Reference’s own tables (correlations of 0.998 or higher), and attempts, free throws and turnovers match official totals within ±2 for every 1,000-minute season. The checks also caught real problems: 16 games missing from the source archive, a 2025-26 change in how the NBA logs end-of-quarter heaves, and Hall of Famers’ playoff seasons filed under a different name.
• Trained an expected-field-goal model (xgboost) on shot location, distance, shot type, game clock and season, but never on who took the shot. It beat a zone-average baseline on a held-out season (log-loss 0.639 vs. 0.657) and is closely calibrated.
• Designed the index from eight components on two axes. Skill: shot-making above expected, self-created makes, shot difficulty and clean footwork. Whistle: free throws beyond what a player’s shot diet predicts, three-point fouls drawn, free-throw share of points, and and-ones on jumpers. I used empirical-Bayes shrinkage so small samples don’t create fake extremes, and standardized everything within season so eras compare fairly.
• Ran a difference-in-differences and event study of the 2021-22 rule change, with a placebo rule date and a separate treatment window to rule out regression to the mean.
• Published it as an eight-page Quarto website with searchable rankings and an interactive player lookup.

What I found

• Steve Nash is the most ethical hooper of the last 30 years (career score 87.7 out of 100), followed by Payton Pritchard, Ish Smith, Nikola Vučević and Chris Paul. James Harden ranks last of 417 qualifying careers (10.7).
• The style is a real, lasting trait: a player’s score correlates 0.74 with the next season’s, and the rankings barely change under alternative weightings (rank correlations of 0.89 to 0.99).
• The crackdown worked league-wide: three-point shooting fouls fell from 1.42 to 1.08 per 100 attempts in one season. The apparent extra drop for prior foul-drawers turned out to be mostly regression to the mean, since a fake “placebo” rule date shows a similar decline.
• But the index predicted who lost efficiency: players with higher pre-rule Whistle Scores lost 0.38 points of true shooting per standard deviation afterward (p = 0.049), while the placebo showed nothing (p = 0.81).

The Ethical Hooper map: every qualifying career, Skill Score vs. Whistle Score

Foul-drawers lost efficiency after the 2021-22 crackdown

Tools: R (data.table, arrow, xgboost, fixest, ggplot2, gt, reactable), Quarto with Observable JS, renv, Git/GitHub.