Chapter 18: Quiz - Team Defensive Analytics

Instructions

Answer all questions. Each question is worth equal points. For multiple choice questions, select the best answer. For calculation questions, show your work.

Multiple Choice Questions

Question 1

What does Defensive Rating measure? - A) Total points allowed per game - B) Points allowed per 100 possessions - C) Opponent field goal percentage - D) Defensive rebounds per game

Answer: B) Points allowed per 100 possessions

Explanation: Defensive Rating is a pace-adjusted metric that measures points allowed per 100 possessions, enabling meaningful comparisons across different eras, teams, and game contexts.

Question 2

In the modern NBA (2020s), what Defensive Rating would be considered elite (top 5)? - A) Below 100 - B) Below 105 - C) Below 108 - D) Below 112

Answer: C) Below 108

Explanation: Due to offensive improvements and pace increases, elite defense in the modern era is approximately below 108, whereas the same rating would have been merely average in earlier eras.

Question 3

What is the approximate league-wide field goal percentage at the rim? - A) 55% - B) 60% - C) 65% - D) 70%

Answer: C) 65%

Explanation: The rim remains the most efficient scoring location, with shots converting at approximately 65% league-wide, making rim protection critically important.

Question 4

A rim protector who holds opponents to 54% at the rim while contesting 8 shots per 36 minutes would be classified as: - A) Below average - B) Average - C) Above average - D) Elite

Answer: D) Elite

Explanation: Elite rim protectors hold opponents to under 55% at the rim AND contest 8+ shots per 36 minutes. Both criteria are met.

Question 5

What percentage of variance in opponent three-point shooting do individual defenders typically explain? - A) 5-10% - B) 10-15% - C) 25-30% - D) 40-50%

Answer: B) 10-15%

Explanation: Research suggests individual defenders explain only 10-15% of variance in opponent three-point shooting, with 65-75% being shooter skill and random variation.

Question 6

The "deterrence effect" in rim protection refers to: - A) Blocked shots - B) Shots that were never taken due to defender presence - C) Fouling to prevent easy baskets - D) Boxing out on rebounds

Answer: B) Shots that were never taken due to defender presence

Explanation: Deterrence captures the shots that were never attempted because of a rim protector's presence - the most difficult but potentially most valuable aspect of rim protection to measure.

Question 7

Why did drop coverage schemes become less dominant after 2020? - A) Rule changes prohibited them - B) Pull-up three-point shooting exploited the space created - C) Teams couldn't find rim protectors - D) Defensive rebounding declined

Answer: B) Pull-up three-point shooting exploited the space created

Explanation: Ball handlers who could shoot threes off the dribble punished dropping bigs, along with lob threats and short-roll playmaking.

Question 8

Defensive Rebound Percentage (DRB%) is calculated as: - A) DRB / Total Team Rebounds - B) DRB / Opponent Missed Shots - C) DRB / (DRB + Opponent ORB) - D) DRB / Minutes Played

Answer: C) DRB / (DRB + Opponent ORB)

Explanation: DRB% measures what percentage of available defensive rebounds (opportunities created by opponent misses) the team or player secures.

Question 9

Which factor most affects the instability of individual defensive metrics? - A) Different referees - B) The collaborative nature of defense - C) Home vs. away games - D) Player fatigue

Answer: B) The collaborative nature of defense

Explanation: Basketball defense is fundamentally collaborative - isolating individual defensive contribution is difficult because all five players must work together, and attribution is inherently problematic.

Question 10

Transition opportunities typically score approximately: - A) 0.85-0.95 PPP - B) 1.00-1.10 PPP - C) 1.15-1.25 PPP - D) 1.30-1.40 PPP

Answer: C) 1.15-1.25 PPP

Explanation: Transition opportunities are among the most efficient in basketball, scoring approximately 1.15-1.25 PPP compared to 1.00-1.10 in halfcourt sets.

Question 11

What is the primary advantage of shot quality metrics (xFG%) over outcome-based metrics (opponent FG%)? - A) Easier to calculate - B) More stable over smaller samples - C) Account for home court advantage - D) Include free throw attempts

Answer: B) More stable over smaller samples

Explanation: Shot quality defense measures process rather than outcomes, making it more stable because it's less affected by opponent shooting variance.

Question 12

The year-to-year correlation for defensive RAPM is approximately: - A) 0.1-0.2 - B) 0.3-0.4 - C) 0.5-0.6 - D) 0.7-0.8

Answer: B) 0.3-0.4

Explanation: This relatively low correlation reflects both measurement limitations and genuine defensive variance based on systems, opponents, and teammates.

Question 13

A "switchable" defender in modern basketball terminology means: - A) Can play multiple offensive positions - B) Can guard multiple positions effectively - C) Can switch between zone and man defense - D) Can change from offense to defense quickly

Answer: B) Can guard multiple positions effectively

Explanation: Teams now explicitly value "switchable" players who can guard positions 1-4 or 2-5, eliminating advantageous switches for opponents.

Question 14

What sample size is typically needed for on-off defensive metrics to stabilize? - A) 500+ minutes - B) 1000+ minutes - C) 2000+ minutes - D) 3000+ minutes

Answer: C) 2000+ minutes

Explanation: On-off defensive metrics only stabilize after approximately 2000+ minutes, highlighting the need for multi-year samples in player evaluation.

Question 15

Second chance points typically account for what percentage of total scoring? - A) 5-8% - B) 12-15% - C) 20-25% - D) 28-32%

Answer: B) 12-15%

Explanation: Second chance points from offensive rebounds account for approximately 12-15% of total scoring, making defensive rebounding crucial.

Question 16

The "contest rate" measures: - A) How often a defender gets a steal - B) How often shots are blocked - C) How frequently a defender contests opponent shots - D) Win percentage in close games

Answer: C) How frequently a defender contests opponent shots

Explanation: Contest rate measures the frequency with which a defender is close enough to an opponent's shot to challenge it, regardless of outcome.

Question 17

Which of the following is NOT a component of elite team defense? - A) Appropriate personnel - B) Coherent scheme - C) High individual usage rates - D) Defensive culture

Answer: C) High individual usage rates

Explanation: Usage rate is an offensive metric. Elite team defense emerges from personnel, scheme, and culture, not offensive ball dominance.

Question 18

The primary limitation of Defensive Rating as a metric is: - A) It doesn't account for pace - B) Attribution to individuals is problematic - C) It can't be calculated for teams - D) It only works for centers

Answer: B) Attribution to individuals is problematic

Explanation: While team DRtg is straightforward, individual DRtg cannot be cleanly calculated because defense is fundamentally collaborative.

Question 19

"Closeout quality" in perimeter defense analysis typically measures: - A) How quickly a player gets back on defense - B) Distance and control when contesting perimeter shots - C) Communication with teammates - D) Boxing out technique

Answer: B) Distance and control when contesting perimeter shots

Explanation: Closeout quality analyzes how close and controlled a defender is when contesting perimeter shots, with tighter closeouts generally leading to lower opponent shooting percentages.

Question 20

Best practices for defensive evaluation include all EXCEPT: - A) Using multi-year samples - B) Integrating video analysis - C) Relying primarily on single-season outcome metrics - D) Considering scheme fit

Answer: C) Relying primarily on single-season outcome metrics

Explanation: Due to high variance, single-season outcome metrics are unreliable. Best practices emphasize multi-year trends, process metrics, and video integration.

Calculation Questions

Question 21

Calculate the Defensive Rating for a game where the team allowed 105 points on the following opponent statistics: - FGA: 88 - FTA: 26 - OREB: 11 - TOV: 13

Answer: Possessions = FGA + 0.44 x FTA - OREB + TOV Possessions = 88 + 0.44 x 26 - 11 + 13 Possessions = 88 + 11.44 - 11 + 13 = 101.44

DRtg = (Points Allowed x 100) / Possessions DRtg = (105 x 100) / 101.44 = 103.5

Question 22

A rim protector contests 7.5 shots per 36 minutes at the rim and holds opponents to 55.2% shooting. League average rim FG% is 65%. Calculate their points saved per 36 minutes.

Answer: FG% difference = 65% - 55.2% = 9.8 percentage points = 0.098

Points saved per contest = 0.098 x 2 points = 0.196 points

Points saved per 36 minutes = 7.5 x 0.196 = 1.47 points

Question 23

Calculate the weighted transition defense efficiency: - Transition possessions: 18% of total - Transition PPP allowed: 1.18 - Half-court possessions: 82% of total - Half-court PPP allowed: 1.05

Answer: Weighted DRtg = (0.18 x 1.18) + (0.82 x 1.05) Weighted DRtg = 0.2124 + 0.861 = 1.073 PPP or 107.3 DRtg

Question 24

A defender's on-off differential shows the team has a 106.2 DRtg when they're on court (2,200 possessions) and 111.8 when off (1,600 possessions). Calculate the weighted team DRtg and the player's defensive impact.

Answer: On-off differential = 111.8 - 106.2 = +5.6 (team is 5.6 points better per 100 possessions with player on)

Weighted team DRtg = (106.2 x 2,200 + 111.8 x 1,600) / (2,200 + 1,600) Weighted team DRtg = (233,640 + 178,880) / 3,800 = 108.6

Question 25

Calculate the expected points from second chances: - Opponent ORB: 12 per game - Second chance conversion rate: 1.15 PPP - Team DRB%: 74%

Answer: Opponent ORB opportunities = 12 / (1 - 0.74) x 0.74 = approximately 34.2 missed shots available

Wait, let me recalculate: If team DRB% is 74%, and opponent gets 12 ORB, then: Total rebound opportunities = 12 / 0.26 = 46.15 Team DRB = 46.15 x 0.74 = 34.15

Second chance points = 12 x 1.15 = 13.8 points per game

True/False Questions

Question 26

TRUE or FALSE: A player with a high block rate is always a good defender.

Answer: FALSE

Explanation: Blocks are only one component of defense. A player might get blocks but fail at other aspects like positioning, help defense, or transition defense. Some elite defenders rarely block shots but excel through positioning and deterrence.

Question 27

TRUE or FALSE: Shot quality defense (xFG%) is more predictive of future defensive performance than opponent actual FG%.

Answer: TRUE

Explanation: Shot quality measures process rather than outcomes, making it more stable and predictive because it's less affected by random shooting variance.

Question 28

TRUE or FALSE: Teams should always prioritize rim protection over perimeter defense.

Answer: FALSE

Explanation: The optimal defensive priority depends on opponent strengths, team personnel, and league trends. In the modern three-point era, perimeter defense has become increasingly important.

Question 29

TRUE or FALSE: The best individual defender on a team will always have the best on-off defensive differential.

Answer: FALSE

Explanation: On-off differential is heavily influenced by lineup effects (who else is playing), opponent quality variation, and sample size. A player could be excellent defensively but have poor on-off numbers due to confounding factors.

Question 30

TRUE or FALSE: Defensive versatility is more valuable in switch-everything schemes than in drop coverage schemes.

Answer: TRUE

Explanation: Switch-everything defense requires every player to guard multiple positions, making versatility essential. Drop coverage can hide limited perimeter defenders by keeping them in the paint.