Key Takeaways: Offensive Line Analytics

One-page reference for Chapter 9 concepts

The O-Line Analytics Challenge

Challenge Implication
No direct stats Must use outcome proxies
Shared responsibility Hard to isolate individuals
Scheme-dependent Zone vs gap affects metrics
QB/RB conflation Can't perfectly separate

Team-Level Pass Protection

protection = (passes
    .groupby('posteam')
    .agg(
        dropbacks=('pass_attempt', 'count'),
        sacks=('sack', 'sum'),
        qb_hits=('qb_hit', 'sum')
    )
)
protection['sack_rate'] = protection['sacks'] / protection['dropbacks']

Sack Rate Interpretation

Sack Rate Quality
< 4% Elite
4-6% Above average
6-8% Average
8-10% Below average
> 10% Poor

Team-Level Run Blocking

def calc_stuff_rate(rushes):
    return (rushes['yards_gained'] <= 0).mean()

def calc_aly(yards):
    if yards < 0: return yards * 1.25
    elif yards <= 4: return yards
    elif yards <= 10: return 4 + (yards - 4) * 0.5
    else: return 4 + 3 + (yards - 10) * 0.25

Stuff Rate Interpretation

Stuff Rate Quality
< 15% Excellent
15-18% Above average
18-22% Average
22-25% Below average
> 25% Poor

Adjusted Line Yards (ALY)

Philosophy: Cap credit for long runs (RB contribution)

Yards Gained Credit
Negative 125% (penalty)
0-4 100%
5-10 50%
10+ 25%

Pressure Definition

pressured = (
    (sack == 1) |
    (qb_hit == 1) |
    (scramble == 1)
)
pressure_rate = pressured.sum() / dropbacks

Data Sources

Metric Source
Sacks, hits Standard PBP
Stuff rate Standard PBP
Individual grades PFF (subscription)
Pressures allowed PFF, SIS
Win rate ESPN/NFL
Time in pocket Next Gen Stats

Individual Evaluation (Requires Charting)

PFF Grades: - 90+: All-Pro - 80-89: Pro Bowl - 70-79: Starter - 60-69: Average - 50-59: Below average - <50: Backup/replacement

Scheme Effects

Scheme Evaluation Impact
Zone Collective grade more meaningful
Power/Gap Individual grades more attributable
Mixed Requires play-by-play tagging

What Metrics Capture

Metric Captures Misses
Sack rate Protection failures QB holds ball
Stuff rate Initial blocking RB vision
ALY Blocking yards Scheme effects
Pressure rate All pressure types Source of pressure

Emerging Metrics

  • Win Rate: % of blocks won (tracking-based)
  • Time to Throw: Pocket duration
  • YBC: Yards before contact (blocking quality)
  • Pressure probability: Expected vs actual

Common Pitfalls

Pitfall Better Approach
All sacks = O-line Consider QB decisions
High YPC = good blocking Check ALY, YBC
Team metrics = individual Need charting data
Ignore scheme Context matters

Evaluation Framework

1. Pass Protection
   - Sack rate
   - Pressure rate
   - Clean pocket EPA

2. Run Blocking
   - Stuff rate
   - ALY
   - Rush success rate

3. Context
   - Scheme type
   - Opponent quality
   - QB/RB contribution

Key Limitations

  • Standard PBP lacks individual data
  • QB and RB always conflate
  • Scheme effects not controlled
  • Opponent adjustment difficult
  • Sample sizes per lineman small

Preview: Chapter 10

Next: Defensive Analytics — evaluating the 11 players trying to stop everything we've analyzed.