Dean Oliver's Four Factors
The foundational framework for basketball success, weighted by statistical importance.
Introduced by Dean Oliver in his seminal 2004 book Basketball on Paper, the Four Factors identify the fundamental components of winning basketball games. Rather than looking at raw points, these factors analyze how teams generate and prevent scoring opportunities on a per-possession basis.
The Factors and Their Weights
Oliver determined that these factors are not equal. He assigned approximate weights to each based on their correlation with winning (using data up to 2003, which still largely holds true today):
| Factor | Formula | Approx. Weight |
|---|---|---|
| 1. Shooting (eFG%) | (FG + 0.5 * 3P) / FGA | 40% |
| 2. Turnovers (TOV%) | TOV / (FGA + 0.44 * FTA + TOV) | 25% |
| 3. Rebounding (ORB%) | ORB / (ORB + Opp DRB) | 20% |
| 4. Free Throws (FT Rate) | FT / FGA | 15% |
Worked Example: 2023-24 Boston Celtics
The Celtics dominated the 2023-24 season by maximizing the most important factor: Shooting. They posted an incredible 57.8% eFG (1st in NBA). Furthermore, they minimized their opponents' eFG to 53.1% (2nd). By winning the 40% factor on both ends of the floor by massive margins, their average performance in rebounding (20% factor) was statistically irrelevant.
Common Mistakes
- Using Raw Rebounds: Never use total rebounds to evaluate rebounding. Use Rebound Percentage (ORB% and DRB%). A team that plays at a fast pace and misses a lot of shots will have more total rebounds simply because there are more opportunities.
- Ignoring FT Rate context: FT Rate is FTs made per FG Attempted, not Free Throw Percentage. It measures the ability to draw fouls, not the ability to convert them.
FAQ
- Have the weights changed in the modern 3-point era?
- While the core tenets remain, modern analysts suggest eFG% has become even more dominant (closer to 45-50% importance) due to the math advantage of the 3-point shot, while ORB% has decreased as teams prioritize transition defense.