Chapter 8 Key Takeaways: Shooting Efficiency Metrics
Essential Concepts Summary
Shooting efficiency metrics quantify how effectively players and teams convert scoring opportunities into points. The progression from basic Field Goal Percentage through Effective Field Goal Percentage to True Shooting Percentage represents increasing sophistication in capturing the full picture of scoring efficiency.
Core Formulas Reference
Field Goal Percentage (FG%)
$$FG\% = \frac{FGM}{FGA} \times 100$$
Purpose: Basic shooting accuracy measure Limitation: Treats all field goals equally regardless of point value
Effective Field Goal Percentage (eFG%)
$$eFG\% = \frac{FGM + 0.5 \times 3PM}{FGA} \times 100$$
Purpose: Accounts for extra value of three-pointers Interpretation: The FG% a player would need shooting only twos to produce same points per shot
True Shooting Percentage (TS%)
$$TS\% = \frac{PTS}{2 \times (FGA + 0.44 \times FTA)} \times 100$$
Purpose: Comprehensive efficiency including free throws Gold Standard: Most complete single measure of scoring efficiency
True Shooting Attempts (TSA)
$$TSA = FGA + 0.44 \times FTA$$
The 0.44 Factor: Weighted average accounting for: - Two-shot fouls (2 FTA = 1 possession) - Three-shot fouls (3 FTA = 1 possession) - And-one free throws (1 FTA, no extra possession) - Technical free throws (no possession cost)
Free Throw Rate (FTr)
$$FTr = \frac{FTA}{FGA}$$
Purpose: Measures foul-drawing ability relative to shot attempts
Three-Point Attempt Rate (3PAr)
$$3PAr = \frac{3PA}{FGA}$$
Purpose: Shot distribution metric showing three-point reliance
Points Per Shooting Attempt (PPS)
$$PPS = \frac{PTS}{TSA}$$
Purpose: Direct measure of points produced per scoring attempt
Expected Value (EV)
$$EV = FG\% \times \text{Point Value}$$
Purpose: Expected points per shot type
Three-Point Break-Even
$$\text{Break-Even 3P\%} = \frac{2}{3} \times 2P\%$$
Purpose: Three-point percentage needed to equal two-point efficiency
Key Metrics Summary
| Metric | What It Measures | When to Use |
|---|---|---|
| FG% | Basic shooting accuracy | Zone-specific analysis, similar shot profiles |
| eFG% | Shooting efficiency accounting for threes | Comparing field goal efficiency |
| TS% | Complete scoring efficiency | Primary scoring evaluation metric |
| FTr | Foul-drawing ability | Understanding scoring style |
| 3PAr | Three-point reliance | Shot selection analysis |
| PPS | Points per opportunity | Direct efficiency comparison |
Efficiency Benchmarks
True Shooting Percentage (Modern Era)
| TS% | Interpretation | Approximate Percentile |
|---|---|---|
| 65%+ | Elite/Historic | 95th+ |
| 62-65% | Excellent | 85th-95th |
| 58-62% | Very Good | 70th-85th |
| 54-58% | Above Average | 50th-70th |
| 50-54% | Below Average | 25th-50th |
| <50% | Poor | Below 25th |
Note: League average TS% is approximately 56-57% in the 2020s era.
Effective Field Goal Percentage
| eFG% | Interpretation |
|---|---|
| 60%+ | Elite efficiency |
| 55-60% | Excellent |
| 50-55% | Above average |
| 45-50% | Average |
| <45% | Below average |
Free Throw Rate
| FTr | Interpretation | Player Type |
|---|---|---|
| 0.50+ | Elite foul drawer | Slasher, post player |
| 0.40-0.50 | Above average | Attack-oriented |
| 0.30-0.40 | Average | Balanced scorer |
| 0.20-0.30 | Below average | Perimeter shooter |
| <0.20 | Low | Jump shooter specialist |
Shot Zone Efficiency Reference
Expected Value by Zone (League Average)
| Zone | Typical FG% | Points | Expected Value |
|---|---|---|---|
| Restricted Area | 64-66% | 2 | 1.28-1.32 |
| Paint (Non-RA) | 38-42% | 2 | 0.76-0.84 |
| Mid-Range | 40-43% | 2 | 0.80-0.86 |
| Corner Three | 38-40% | 3 | 1.14-1.20 |
| Above Break Three | 35-37% | 3 | 1.05-1.11 |
The Mid-Range Dead Zone
Mid-range shots (10-22 feet, excluding three-pointers) typically yield: - Lowest expected value in basketball - ~0.80-0.86 points per attempt - Below both rim attempts (1.28+) and three-pointers (1.05+)
The Three-Point Revolution
Historical Three-Point Attempt Evolution
| Era | League 3PA/Game | 3P% | Three-Point EV |
|---|---|---|---|
| 1990s | 12-15 | 34-35% | 1.02-1.05 |
| 2000s | 15-18 | 35-36% | 1.05-1.08 |
| 2010-15 | 20-24 | 35-36% | 1.05-1.08 |
| 2015-20 | 28-35 | 35-36% | 1.05-1.08 |
| 2020s | 35+ | 36-37% | 1.08-1.11 |
Why Three-Point Shooting Increased
- Mathematical advantage: Higher EV than mid-range
- Spacing benefits: Opens driving lanes
- Analytics adoption: Front offices recognized value
- Player development: Youth training emphasized shooting
- Rule changes: Freedom of movement helped shooters
Efficiency Analysis Checklist
Before Evaluating a Player
- [ ] Calculated TS% (not just FG%)
- [ ] Considered shot volume (TSA/game or Usage)
- [ ] Examined shot distribution (3PAr, zone breakdown)
- [ ] Compared to era-appropriate benchmarks
- [ ] Accounted for role context (primary vs. secondary scorer)
- [ ] Checked free throw rate contribution
Quality Control Questions
- Is the sample size sufficient for reliability?
- What is the player's role and team context?
- How does efficiency compare to usage level?
- Are efficiency metrics consistent with shot profile?
- What does zone-specific analysis reveal?
Common Mistakes to Avoid
Mistake 1: Using FG% for Perimeter Players
Problem: FG% penalizes three-point shooters Solution: Always use eFG% or TS% for overall efficiency
Mistake 2: Ignoring Free Throws in Efficiency
Problem: eFG% misses free throw contribution Solution: TS% captures complete scoring picture
Mistake 3: Comparing Volume and Efficiency Separately
Problem: High efficiency at low volume is different from high efficiency at high volume Solution: Consider efficiency in context of TSA or Usage Rate
Mistake 4: Applying Modern Benchmarks to Historical Players
Problem: League average TS% has changed over time Solution: Compare to era-appropriate averages
Mistake 5: Treating Expected Value as Deterministic
Problem: EV analysis assumes large samples; variance matters Solution: Acknowledge variance especially in small samples (playoffs)
Key Relationships
TS% vs. eFG%
$$TS\% - eFG\% \approx \text{Free Throw Contribution}$$
Players with high FTr will have TS% noticeably higher than eFG%.
eFG% vs. FG%
$$eFG\% - FG\% = \frac{0.5 \times 3PM}{FGA} \times 100$$
The "three-point bonus" - increases with both 3PM and 3PAr.
Volume-Efficiency Trade-off
As usage increases: - Shot difficulty typically increases - Efficiency tends to decrease - Exceptional players maintain high efficiency despite volume
Historical Context
Elite TS% Seasons (High Volume)
| Player | Season | PPG | TS% | Context |
|---|---|---|---|---|
| Stephen Curry | 2015-16 | 30.1 | 66.9% | Record-setting |
| Kevin Durant | 2013-14 | 32.0 | 63.5% | MVP season |
| LeBron James | 2013-14 | 27.1 | 64.9% | Exceptional |
| Giannis | 2019-20 | 29.5 | 61.3% | MVP season |
League Average TS% by Era
| Era | League Avg TS% |
|---|---|
| 1990s | 52-53% |
| 2000s | 53-54% |
| 2010s | 54-56% |
| 2020s | 56-58% |
Quick Reference Conversions
From FG% to Approximate TS%
For players with typical shot distributions:
TS% ≈ FG% + 7-10%
From eFG% to Expected PPS
Expected PPS ≈ eFG% × 2 / 100
(50% eFG% = 1.00 PPS)
From TS% to Expected PPS
PPS = TS% × 2 / 100
(60% TS% = 1.20 PPS)
Chapter Summary Statement
True Shooting Percentage represents the gold standard for measuring scoring efficiency because it incorporates all scoring methods: two-pointers, three-pointers, and free throws. Understanding the relationship between TS%, eFG%, and shot distribution enables proper evaluation of players across different roles and eras. The three-point revolution transformed shot selection by revealing the mathematical superiority of three-pointers over mid-range shots, fundamentally changing how basketball is played.
Looking Ahead
Chapter 9 introduces advanced box score metrics like PER, Game Score, and Usage Rate that incorporate shooting efficiency alongside other statistics to create comprehensive player evaluation frameworks. These metrics build on the efficiency concepts established here while attempting to capture a player's complete statistical contribution.