Several possession value frameworks exist in modern football analytics. Knowing the differences helps you pick the right tool.
Expected Threat (xT)
Created by Karun Singh, xT divides the pitch into zones with assigned values based on historical scoring rates. Players get credit for moving the ball to higher-value zones.
Advantages: Simple, interpretable, stable game-to-game
Limitations: Does not value defensive actions, ignores context like pressure and score differential
For a deeper dive, see our complete guide to Expected Threat (xT) in football analytics.
StatsBomb On-Ball Value (OBV)
Built on StatsBomb's xG model, OBV includes both goals for and goals against components. It deliberately excludes possession history features to avoid bias toward players on stronger teams.
Advantages: Reduces team strength bias
Limitations: Proprietary, not widely available outside StatsBomb clients
Uses a 10-second time window rather than counting actions. Originally punished ball losses heavily, but revised to reward even unsuccessful actions that end in dangerous areas.
Advantages: Time-based approach may capture game flow better
Limitations: Less academic validation than VAEP
Which Should Bettors Use?
The research comparison between xT and VAEP reveals something counterintuitive. xT achieves correlation of 0.89 for position-based values. VAEP achieves only 0.25. That lower correlation is actually a strength.
"The entire goal of innovation is to capture new information that current metrics miss. Therefore, a high correlation with existing metrics should be viewed with skepticism, not as a badge of honor."
— DTAI Sports Analytics Lab
VAEP's lower correlation reflects greater contextual complexity. For bettors, this means VAEP is more likely to surface value the market has not spotted yet.
For a comprehensive overview of all possession value frameworks, see our guide to possession value models in football analytics.