Capstone - Complete Analytics System
19.1 The Tracking Data Revolution
Tracking data captures every movement on the pitch at 25 frames per second, providing unprecedented insight into player positioning, team shape, and off-ball activity. This chapter explores how to work with this powerful data source.
Learning Objectives
- Understand tracking data structure and providers
- Calculate physical metrics (distance, speed, acceleration)
- Analyze team formations and defensive shape
- Measure pressing intensity and compactness
- Understand Expected Threat (xT) models
Tracking vs Event Data
| Aspect | Event Data | Tracking Data |
|---|---|---|
| What it captures | Actions on the ball | All player positions, every frame |
| Frequency | ~2000 events/match | ~3 million data points/match |
| Off-ball info | Limited | Complete |
| Availability | Widely available (free options) | Premium/restricted access |
| Cost | Free to moderate | Expensive |
| Providers | StatsBomb, Opta, Wyscout | Second Spectrum, SkillCorner, Metrica |
Tracking Data Structure
Each frame contains:
Timestamp
- Frame number
- Match time
- Period
Player Positions
- X, Y coordinates (all 22 players)
- Player ID
- Team affiliation
Ball Position
- X, Y coordinates
- Z (height) when available
- Ball status (in play, dead)
19.2 Physical Performance Metrics
Tracking data enables precise measurement of player physical output.
Key Physical Metrics
| Metric | Definition | Elite Benchmark |
|---|---|---|
| Total Distance | Total meters covered per 90 | 10-12 km |
| High-Speed Running (HSR) | Distance at 19-25 km/h | 800-1200m |
| Sprinting | Distance at >25 km/h | 200-400m |
| Sprint Count | Number of sprints per 90 | 30-50 |
| Top Speed | Maximum velocity reached | 32-36 km/h |
| Accelerations | High-intensity accelerations | 40-60 |
19.3 Formation and Shape Analysis
Tracking data allows precise measurement of team formations and defensive shape throughout a match.
- Calculate average positions
- Cluster into lines/rows
- Identify formation pattern
- Track formation changes
- Team width and length
- Compactness (area)
- Defensive line height
- Line breaking passes
19.4 Pressing and Compactness
Tracking data enables precise measurement of pressing intensity and team compactness.
19.5 Expected Threat (xT)
Expected Threat quantifies the goal probability increase from moving the ball between pitch zones. It values all ball movements, not just shots.
xT Concept
xT = P(scoring | zone after) - P(scoring | zone before)
Positive xT = ball moved to more dangerous position
19.6 Space Control and Pitch Control
Pitch control models estimate which team is more likely to gain possession of a ball placed at any point on the pitch.
Pitch Control Factors
- Distance to point: Closer players have higher control
- Velocity: Players moving toward the point have advantage
- Reaction time: Time to change direction
- Maximum speed: How fast players can reach the point
19.7 Practice Exercises
Exercise 19.1: Full Match Physical Analysis Dashboard
Task: Calculate comprehensive physical metrics for all 22 players in a match including distance, speed zones, sprints, and accelerations. Create position-based comparisons and visualizations.
Exercise 19.2: Pressing Intensity Score System
Task: Build a composite pressing intensity metric combining distance to ball, number of pressers, closing speed, and compactness. Track how pressing varies by match period, score state, and zone.
Exercise 19.3: Expected Threat Model & Player Rankings
Task: Build an xT model with proper grid training, calculate xT added for all passes/carries in a match, and rank players by total xT contribution with visualization.
19.8 Chapter Summary
Key Takeaways
- Tracking data captures all 22 players at 25fps, enabling off-ball analysis
- Physical metrics include distance, speed zones, sprints, and accelerations
- Formation analysis measures team shape, width, length, and defensive line
- Pressing metrics quantify defensive intensity and compactness
- Expected Threat (xT) values ball movements based on goal probability
- Pitch control estimates which team would win possession at any point
Next Steps
In Chapter 20, we'll explore player recruitment and scouting, bringing together all our analytical tools to identify and evaluate transfer targets.